msm: smd: SMD memcpy refactor

SMD uses memcpy() that does a byte copy. This results in consumption of
extra time and in some targets, on which only word access is allowed, the
copy of data doesn't happen.

Change the memcpy function to a SMD specific copy function that does a 4
byte copy to a 4 byte aligned address.

CRs-Fixed: 551738
Change-Id: I94e99ee45979f62f82de61d88e8fea9d29299a58
Signed-off-by: Zaheerulla Meer <zmeer@codeaurora.org>