ARM: dts: msm: Add memory mapped timer support for 8939

Add memmory mapped qtimer which can be used as
broadcast timer into the device tree.

Change-Id: I484f2981f7ea92cbd5dcaf0d4a30349654211804
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Xiaocheng Li <lix@codeaurora.org>