[PATCH] mxc: Fix pad names for imx51

The pads capable of being used as GPIOs had their pad-name and mode-name
switched. Also, fix the following:

- Whitespace fixes
- Replace IOMUX_CONFIG_ALTn with 'n'

Signed-off-by: Amit Kucheria <amit.kucheria@canonical.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>