msm: scm: Add scm_call_atomic3

Some drivers need to pass three arguments atomically. Add support
for it.

Change-Id: Id0f962400c5c4f721eef44069fc3db1779248ae3
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Carter Cooper <ccooper@codeaurora.org>
ARM: Add support for 64 bit register reads/writes

Add macros to read and write to 64 bit registers.

Change-Id: Id45d4086aa148ba96df3987c3341c133f1c56541
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Signed-off-by: Iliyan Malchev <malchev@google.com>