MLK-13373 mx6sll: update ddr script to 2.1.1

Update ddr script to 2.1.1

Script:
http://compass.freescale.net/livelink/livelink/235732623/EVK_IMX6SLL_LPDDR3_400MHz_512MB_32bit_V2.1.1.txt?func=doc.Fetch&nodeid=235732623



Version 2.1.1:
  -Update [MMDC_MPRDDLCTL] and [MMDC_MPWRDLCTL] based on calibration results
  -setmem /32 0x021B0848 = 0x3F393B3C   // [MMDC_MPRDDLCTL] MMDC PHY Read delay-lines Configuration Register
  -setmem /32 0x021B0850 = 0x262C3826  // [MMDC_MPWRDLCTL] MMDC PHY Write delay-lines Configuration Register

Tested on two boards.

Signed-off-by: Peng Fan <peng.fan@nxp.com>