ixp4xx: switch cambira to gpio_keys_polled

gpio_buttons have been deprecated since a long time.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@37434 3c298f89-4303-0410-b956-a3cf2f4a3e73
x86: switch rdc to to gpio_keys_polled

gpio_buttons have been deprecated since a long time.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@37435 3c298f89-4303-0410-b956-a3cf2f4a3e73
kernel: remove gpio_buttons

It hasn't been buildable for a long time, and there are no users of it
anymore left as all of them have been switched to the upstream accepted
version.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@37436 3c298f89-4303-0410-b956-a3cf2f4a3e73