mb/google/rex: Enable touchpad

Enable touchpad for Google Rex.

BUG=b:245866939
TEST=Build and boot to Google Rex. Verify touchpad works.

Signed-off-by: Kapil Porwal <kapilporwal@google.com>
Change-Id: I49fdd72bf3350085e82411b95edcd6a9a09d2df5
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67471
Reviewed-by: Tarun Tuli <taruntuli@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Shaunak Saha <shaunak.saha@intel.corp-partner.google.com>
diff --git a/src/mainboard/google/rex/Kconfig b/src/mainboard/google/rex/Kconfig
index 367cf09..bda753b 100644
--- a/src/mainboard/google/rex/Kconfig
+++ b/src/mainboard/google/rex/Kconfig
@@ -3,6 +3,7 @@
 	# FIXME: Rex Proto 0 only has 64MB SPINOR mounted on the board,
 	# and the plan is to use 32MB later with Proto 1 onwards.
 	select BOARD_ROMSIZE_KB_65536
+	select DRIVERS_I2C_GENERIC
 	select EC_GOOGLE_CHROMEEC
 	select EC_GOOGLE_CHROMEEC_BOARDID
 	select EC_GOOGLE_CHROMEEC_ESPI