mm: clear MMU mapping for secure os memory [1/1]

mm: clear MMU mapping for secure os memory [1/1]

PD#SWPL-1631

Problem:
If Cortex A73 accessed memory near secure memory range, an
SError may occur due to prefetch of A73 core.

Solution:
Remove mmu maping of secure memory range.
Note: must add clear-map and set clear range property in DTS

Verify:
W400

Change-Id: I718919c1b4873584eb87e00332622a1626672808
Signed-off-by: tao zeng <tao.zeng@amlogic.com>