bcm27xx: bcm2710: update defconfig

Ran `make kernel_menuconfig CONFIG_TARGET=bcm2710` having used the snapshot
config for bcm2710[1].  Manually added back two symbols that the make target
removed, namely:
* # CONFIG_SND_SOC_AD193X_I2C is not set
* # CONFIG_SND_SOC_AD193X_SPI is not set

1. https://downloads.openwrt.org/snapshots/targets/bcm27xx/bcm2710/config.buildinfo

Signed-off-by: John Audia <graysky@archlinux.us>

target/linux/bcm27xx/bcm2710/config-5.10

@@ -37,8 +37,6 @@ CONFIG_ARM64_VA_BITS=39
 CONFIG_ARM64_VA_BITS_39=y
 CONFIG_ARM64_VHE=y
 CONFIG_ARM64_WORKAROUND_CLEAN_CACHE=y
-CONFIG_ARM64_WORKAROUND_REPEAT_TLBI=y
-CONFIG_ARM64_WORKAROUND_SPECULATIVE_AT=y
 CONFIG_ARM_AMBA=y
 CONFIG_ARM_ARCH_TIMER=y
 CONFIG_ARM_ARCH_TIMER_EVTSTREAM=y