feat(imx8ulp): adjust the dram mapped region

below commit mapped 16 MB memory from the start of DRAM(0x80000000),
which may have conflict with the shared memory used by Trusty OS:
  LF-8819: plat: imx8ulp: ddrc switch auto low power and software interface

change the mapped memory to 'vdev0buffer' reserved memory (0x8ff00000)
to avoid memory conflict. This commit also bumps the XTLB tables
to avoid mapping failure.

Signed-off-by: Ji Luo <ji.luo@nxp.com>
Change-Id: I1a7af958af47e3fc9955d0a80d1649971e843eab
2 files changed