mx6: Support SKS-Kinkel sksimx6 Board

Board  has 1GB RAM and boots from SD Card

U-Boot SPL 2018.01-rc3-00005-ga1898b8 (Jan 02 2018 - 13:48:54)
BT_FUSE_SEL already fused, will do nothing
Trying to boot from MMC1

U-Boot 2018.01-rc3-00005-ga1898b8 (Jan 02 2018 - 13:48:54 +0100)

CPU:   Freescale i.MX6DL rev1.2 996 MHz (running at 792 MHz)
CPU:   Commercial temperature grade (0C to 95C) at 40C
Reset cause: POR
I2C:   ready
DRAM:  1 GiB
MMC:   FSL_SDHC: 0
In:    serial
Out:   serial
Err:   serial
Net:   FEC [PRIME]

Signed-off-by: Stefano Babic <sbabic@denx.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>