sb/ich7: Use common/gpio.h to set up GPIOs

This is more consistent with newer Intel targets.

This a static struct so it is initialized to 0 by default.
To make it more readable:
* only setting to GPIO mode is made explicit;
* only pins in GPIO mode are either set to input or output since this
  is ignored in native mode;
* only output pins are set high or low, since this is read-only on
  input;
* blink is only operational on output pins, non-blink is not set
  explicitly;
* invert is only operational on input pins, non-invert is not set
  explicitly.

Change-Id: I05f9c52dee78b7120b225982c040e3dcc8ee3e4e
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/17639
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/src/mainboard/gigabyte/ga-945gcm-s2l/Makefile.inc b/src/mainboard/gigabyte/ga-945gcm-s2l/Makefile.inc
index f9621db..f3d7e76 100644
--- a/src/mainboard/gigabyte/ga-945gcm-s2l/Makefile.inc
+++ b/src/mainboard/gigabyte/ga-945gcm-s2l/Makefile.inc
@@ -1 +1,2 @@
 ramstage-y += cstates.c
+romstage-y += gpio.c