mb/google/skyrim: Disable cardbus support

Skyrim does not have a cardbus socket, so disable it.

Maybe cardbus support shouldn't be enabled by default?

BUG=None
TEST="PC Card (PCMCIA) is supported" no longer shows up
in dmidecode output.

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: Ic941b075e8b5082b5e61e728a77fd79c0ebba35e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/73167
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jason Glenesk <jason.glenesk@amd.corp-partner.google.com>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>

src/mainboard/google/skyrim/Kconfig

@@ -181,4 +181,7 @@ config ENABLE_STB_SPILL_TO_DRAM
 	  just the small SRAM buffer to a much larger area reserved in main
 	  memory.
 
+config CARDBUS_PLUGIN_SUPPORT
+	default n
+
 endif # BOARD_GOOGLE_BASEBOARD_SKYRIM