input: qcom-hv-haptics: Deglitch fifo-empty interrupt

Check INT_RT_STS in FIFO empty IRQ handler and ignore the interrupt
if FIFO_EMPTY real time status bit is not set.

Change-Id: I7a276fa1d8c79d530fc26f74263e0608096a99f8
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>