ENGR00315894-60 GPIO: Modify driver mxc_gpio to support RDC Semaphores

ENGR00315894-60 GPIO: Modify driver mxc_gpio to support RDC Semaphores

For GPIO group which shared by multiple masters, it may set in RDC
to shared and semaphore required. Before access the GPIO register,
the GPIO driver must get the RDC semaphore, and release the semaphore
after the GPIO register access.

When CONFIG_MXC_RDC is set, the features related to RDC semaphores
is enabled in mxc_gpio driver.

Signed-off-by: Ye.Li <B37916@freescale.com>
(cherry picked from commit 84d63e2e2ce12f714e88baad8b2325684614a7c1)
Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Conflicts:
	drivers/gpio/mxc_gpio.c

(cherry picked from commit c9943b9c8a78bb2c9886bfe582e82978387d8dee)
Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
(cherry picked from commit faf94726cac8316c4342e19936f1e03ef283ace3)
(cherry picked from commit 6c0474fe0e4fc543c62b22c05c2702a881f56418)
(cherry picked from commit 7cd5fec7ce6a9ecfdaa1a9c1aaaa0d0ac18a4f86)
(cherry picked from commit 74d68c1b9f098c44992d591616372f0ec5ff13dd)