boards/config: Remove final mentions of NSH_ARCHINIT

[linguini1]

Summary

Since NSH_ARCHINIT is now removed, this commit cleans the last few references to this option in the defconfig files that were recently modified and escaped removal in initialization simplification commit.

Connected to #18408.

Impact

Existing configurations no longer rely on NSH_ARCHINIT, but instead use
BOARD_LATE_INITIALIZE.

Testing

esp32p4-function-ev-board:nsh build after change:

CPP:  /home/linguini/coding/nuttx-space/nuttx/boards/risc-v/esp32p4/esp32p4-function-ev-board/../common/scripts/esp32p4_aliases.ld-> /home/linguini/coding/nuttx-space/nuttx/bCPP:  /home/linguini/coding/nuttx-space/nuttx/boards/risc-v/esp32p4/esp32p4-function-ev-board/../common/scripts/esp32p4_flat_memory.ld-> /home/linguini/coding/nuttx-space/nutCPP:  /home/linguini/coding/nuttx-space/nuttx/boards/risc-v/esp32p4/esp32p4-function-ev-board/../common/scripts/esp32p4_sections.rev3.ld-> /home/linguini/coding/nuttx-space/nCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.eco5.ld-> /home/linguini/coding/nuttx-space/nuttCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.eco5.libc.ld-> /home/linguini/coding/nuttx-spaceCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.eco5.libgcc.ld-> /home/linguini/coding/nuttx-spaCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.api.ld-> /home/linguini/coding/nuttx-space/nuttxCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.version.ld-> /home/linguini/coding/nuttx-space/nCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.libc-suboptimal_for_misaligned_mem.ld-> /home/liCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.systimer.ld-> /home/linguini/coding/nuttx-space/CPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/soc/esp32p4/ld/esp32p4.peripherals.ld-> /home/linguini/coding/nuttx-space/nuttxCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/riscv/ld/rom.api.ld-> /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/cCPP:  /home/linguini/coding/nuttx-space/nuttx/arch/risc-v/src/chip/esp-hal-3rdparty/components/esp_rom/esp32p4/ld/esp32p4.rom.eco5.newlib.ld-> /home/linguini/coding/nuttx-spaLD: nuttx
Memory region         Used Size  Region Size  %age Used
   tcm_idram_seg:          68 B         8 KB      0.83%
        irom_seg:      135162 B        64 MB      0.20%
        sram_seg:       35180 B     847808 B      4.15%
        drom_seg:      241368 B        64 MB      0.36%
rev3_mspi_workaround_seg:           0 B          0 B
      lp_ram_seg:         104 B      32744 B      0.32%
 lp_reserved_seg:           0 B         24 B      0.00%
  extern_ram_seg:           0 B        64 MB      0.00%
CP: nuttx.hex
MKIMAGE: NuttX binary
esptool.py -c esp32p4 elf2image --ram-only-header -fs 4MB -fm dio -ff "80m" -o nuttx.bin nuttx
Warning: DEPRECATED: 'esptool.py' is deprecated. Please use 'esptool' instead. The '.py' suffix will be removed in a future major release.
esptool v5.2.0
Creating ESP32-P4 image...
Image has only RAM segments visible. ROM segments are hidden and SHA256 digest is not appended.
Merged 2 ELF sections.
Successfully created ESP32-P4 image.
Generated: nuttx.bin