mb/google/slippy: Select board-specific options per board

Move board-specific selects out of common configuration and add them to
each board where necessary.

Change-Id: I1cfea0491f707052db2fbcee078e2c27c5a306c5
Signed-off-by: Felix Singer <felixsinger@posteo.net>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/60353
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
diff --git a/src/mainboard/google/slippy/Kconfig b/src/mainboard/google/slippy/Kconfig
index 12d0c26..0148093 100644
--- a/src/mainboard/google/slippy/Kconfig
+++ b/src/mainboard/google/slippy/Kconfig
@@ -1,7 +1,6 @@
 config BOARD_GOOGLE_BASEBOARD_SLIPPY
 	def_bool n
 	select BOARD_ROMSIZE_KB_8192
-	select DRIVERS_I2C_RTD2132 if BOARD_GOOGLE_LEON
 	select EC_GOOGLE_CHROMEEC
 	select EC_GOOGLE_CHROMEEC_LPC
 	select HAVE_ACPI_RESUME
@@ -24,6 +23,7 @@
 
 config BOARD_GOOGLE_LEON
 	select BOARD_GOOGLE_BASEBOARD_SLIPPY
+	select DRIVERS_I2C_RTD2132
 
 config BOARD_GOOGLE_PEPPY
 	select BOARD_GOOGLE_BASEBOARD_SLIPPY