MLK-13280 ARM: imx: missing mmdc read fifo reset on resume

MLK-13280 ARM: imx: missing mmdc read fifo reset on resume

When a device like (USB, CAMM, tty, etc) prevents the megamix
domain to power down during the suspend process (by enabling
a wakeup source) the resume process goes through a path where
the MMDC context should not be restored. However this resume
path does not reset the read fifo MMDCx_MPDGCTRL0[RST_RD_FIFO]
for the platforms with LPDDR2 causing a bad resuming and reset
of the device due to an exception.

This patch adds the reset_read_fifo on the No-restoring-MMDC
path to fix the bad resuming.

Signed-off-by: Juan Gutierrez <juan.gutierrez@nxp.com>
Signed-off-by: Alejandro Sierra <b18039@freescale.com>