ARM: imx50: correct iomux-mx50.h wrong daisy chain settings

Most fix is for uart txd/cts. They don't need to select input.
And fix some other pads with wrong select input.

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>