Put an SOC prefix on each GPIO register definition, eliminating the
need to have SOC ifdefs around the definitions.

Change-Id: I5a01fd328a89ce1be610847934d6e118f5465e42
Signed-off-by: David Brown <davidb@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>