drm/panel: rpi: Drop unused GPIO includes

The Rpi panel driver doesn't use any symbols from these
GPIO includes so just drop them.

Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203152655.159281-1-linus.walleij@linaro.org