ARM: qcom: Enable GENERIC_CLOCKEVENTS_BROADCAST for sdxpoorwills

Enable Broadcast timer support for uniprocessor systems. When a CPU
enters power collapse, the system timers are held in reset and the CPU
relies on the broadcast timers to wakeup the CPU up for timer events.

Change-Id: I71108ff42ccc3a133c62c6b801f7f995bfec370f
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>