soc: qcom: smem: Move to arch_initcall()

The SMEM driver is critical to the boot process of qcom System on Chips
(SoC).  Some SMEM clients use SMEM to communicate with remote processors
on the SoC to perform boot critical functions, such as submitting clock
votes to a power management processor.  As a result of being in this
critical path for boot, the SMEM driver should be initialized as early as
possible to unblock the entire boot process.

Call SMEM's init() from arch_initcall() to initialize SMEM as early as
possible in boot.

Change-Id: I837b8a93f721d7f9740539f16df1625e8febfbd4
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>