ARM: 5957/1: ARM: RealView SD/MMC Card detection and write-protect using GPIOLIB

The switch to using GPIOLIB broke the sd/mmc card detection on the
RealView development boards if GPIO_PL061 was not selected.
This patch selects GPIO_PL061 if GPIOLIB is selected.
The sense of the return value from mmc_status has also changed
and is corrected.

Signed-off-by: Colin Tuckley <colin.tuckley@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>