ARM: i.MX IOMUX-V3 replace struct pad_desc with bitmapped cookie

The following patch is a first step to convert the 'struct pad_desc'
to a bitmapped cookie to facilitate adding platform specific pullup or
drive strength definitions to existing pad definitions without need to
rewrite the complete pad def.

The patch wraps 'struct pad_desc' in an opaque data type and
introduces macros to access the individual members.
This patch does not constitute any functional change!

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx5/board-mx51_3ds.c b/arch/arm/mach-mx5/board-mx51_3ds.c
index 79ce8dc..ba5805f 100644
--- a/arch/arm/mach-mx5/board-mx51_3ds.c
+++ b/arch/arm/mach-mx5/board-mx51_3ds.c
@@ -30,7 +30,7 @@
 #define EXPIO_PARENT_INT	(MXC_INTERNAL_IRQS + GPIO_PORTA + 6)
 #define MX51_3DS_ECSPI2_CS	(GPIO_PORTC + 28)
 
-static struct pad_desc mx51_3ds_pads[] = {
+static iomux_v3_cfg_t mx51_3ds_pads[] = {
 	/* UART1 */
 	MX51_PAD_UART1_RXD__UART1_RXD,
 	MX51_PAD_UART1_TXD__UART1_TXD,