mb/google/peach_pit: Select BOOT_DEVICE_NOT_SPI_FLASH

CPU_SAMSUNG_EXYNOS5420 has its own boot device implementation
(src/soc/samsung/exynos5420/alternate_cbfs.c), so
BOOT_DEVICE_NOT_SPI_FLASH should be selected.

Change-Id: I0a9f96ad68b28773ede4e99510bd33867789e185
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/65109
Reviewed-by: Paul Menzel <paulepanter@mailbox.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/peach_pit/Kconfig

@@ -4,6 +4,7 @@ if BOARD_GOOGLE_PEACH_PIT
 
 config BOARD_SPECIFIC_OPTIONS
 	def_bool y
+	select BOOT_DEVICE_NOT_SPI_FLASH
 	select CPU_SAMSUNG_EXYNOS5420
 	select EC_GOOGLE_CHROMEEC
 	select EC_GOOGLE_CHROMEEC_SPI