s32k1xx: Allow building with debug features and no console.

[csanchezdll]

Summary

If no LPUART console is selected, but DEBUG_FEATURES is enabled, building fails for s32k1xx boards.

Impact

This prevents using custom consoles different from LPUART based ones.

Testing

1. tools/configure.sh s32k148evb:nsh
2. make menuconfig

• Device Drivers -> Serial Driver Support -> Serial console: select "No serial console"
• Build Setup -> Debug Options -> Enable Debug Features: check

3. make
   Build fails:

                 from chip/s32k1xx_lowputc.c:36:
chip/s32k1xx_lowputc.c: In function 's32k1xx_lowputc':
chip/s32k1xx_lowputc.c:391:20: error: 'S32K1XX_CONSOLE_BASE' undeclared (first use in this function); did you mean 'S32K1XX_GPIOE_BASE'?
  391 |   while ((getreg32(S32K1XX_CONSOLE_BASE + S32K1XX_LPUART_STAT_OFFSET) &
      |                    ^~~~~~~~~~~~~~~~~~~~```

After applying the PR, build succeeds with the same procedure.

[hartmannathan]

LGTM