Use shared gpio code from common folder.
Remove the now unused bd82x6x/gpio.c.
Needs test on real hardware !
Change-Id: Ibb54c03fd83a529d1ceccfb2c33190e7d42224d8
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/13616
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>