gpio: gpio-msm-v2/v3: Fix spurious interrupts when gpio-irq is unmasked

To unmask a gpio interrupt, the gpio driver sets the
INTR_RAW_STATUS_EN and INTR_ENABLE bits in the INTR_CFG register.
As soon as the INTR_RAW_STATUS_EN is set, the INTR_STATUS is updated
and this causes a spurious interrupt when the irq is enabled.
This is noticed frequently when the gpio is pulled high and requests
a rising edge interrupt or pulled low and is requesting a falling edge
interrupt.
Due the internal circuit design of the TLMM IRQ block, the above method
causes a spurious interrupt when the irq was initialized.
Hence, to avoid this behavior we set the INTR_RAW_STATUS_EN, clear the
INTR_STATUS only once during setup. Every mask and unmask only toggles
the INTR_ENABLE bit.

CRs-Fixed: 346861
Change-Id: I1c9852ed91432582c3d050ccf933053fd368b216
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
Signed-off-by: Taniya Das <tdas@codeaurora.org>