mb/lenovo/x201: Link gpio map instead of including a header

Linking should allow to link depending on possible future variants.
E.g. in Makefile.inc romstage-$(CONFIG_'VARIANT0') += gpio_variant0.c
etc.

Change-Id: I88b5ef8e12ac606751952a493f626e1b146e98f7
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/19139
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
3 files changed