ARM: dts: msm: Mount the system partition during early init

Add support to early mount system partition so that system
modules can be loaded during early init for msm8917, msm8937,
msm8953 and msm8996.

Change-Id: I9d75bec6ff9bada5ab2db6de2a58e40323aa6ca2
Signed-off-by: Swetha Chikkaboraiah <schikk@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>