uboot-imx

icorem6: Use proper iomux_ddr_regs drive strength values

Usually the drive strength values for DQ and SDL are 0x30 and
0x28 respectively, update them accordingly.

Cc: Stefano Babic <sbabic@denx.de>
Cc: Matteo Lisi <matteo.lisi@engicam.com>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>