linux-wandboard

MLK-12371: ARM: imx: suspend-imx7: correct HW_ANADIG_SNVS_MISC_CTRL set

To avoid touch other bits of HW_ANADIG_SNVS_MISC_CTRL , use set/clear register
, and correct the bit29 setting:
  --before: write 1 to toggle DDR power pin to high before enter DDR retention,
            and write 1 again to pull pin to low when exit from DDR retention.
  --now: write 1 to pull DDR power pin to high and write 0 to low.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>