ENGR00279946 dts: imx6qdl-sabreauto: add baseboard sd card slot support

ENGR00279946 dts: imx6qdl-sabreauto: add baseboard sd card slot support

NOTE since SD Card in main board takes a long route hence with
Drive Speed High 80 OHMS causing error on high speed cards.
Per suggestion DSE 40 OHMS is used.

And the SD1 on sabreauto baseboard is conflict with gpmi nand.
The conflict pins are DAT4~DAT7. Since the SD3 on cpu board
already supports 8 bit bus width, we do not want add an extra
dts file for it, so we disable 8 bit and use 4 bit width for
this issue.

[haibo chen:
    cherry-pick commit e38226f4cbf222ce9377963e20fe5f1d7103a2af
	cherry-pick commit 3807ed7ac39ec402f19bb27d2d60ceb3ce5448b2
	from imx_3.10.y]
Signed-off-by: Haibo Chen <haibo.chen@freescale.com>