soc: qcom: spss_utils: read spu uefi apps calculated cmac

The spu firmware and 3 apps are loaded by UEFI.
The spu calculates the apps cmac and compares with
the saved cmac. on mismatch the spu perform CE.
The SPU stores the calculated cmac in shared memory.
This driver reads the new calculated cmac from memory.
The spu daemon will fetch them during boot via sysfs
and save them in the file system.

Change-Id: I03660670b54d86b6b6f4b8db891834d8f6b8dcc3
Signed-off-by: Amir Samuelov <amirs@codeaurora.org>