pinctrl: qcom: Add irq_enable callback for msm gpio

Introduce the irq_enable callback which will be same as irq_unmask
except that it will also clear the status bit before unmask.

This will help in clearing any erroneous interrupts that would
have got latched when the interrupt is not in use.

There may be devices like UART which can use the same gpio line
for data rx as well as a wakeup gpio when in suspend. The data that
was flowing on the line may latch the interrupt and when we enable
the interrupt before going to suspend, this would trigger the
unexpected interrupt. This change helps clearing the interrupt
so that these unexpected interrupts gets cleared.

Change-Id: Ia22b226856c5d113f349a88b23126d3ea33465d6
Signed-off-by: Srinivas Ramana <sramana@codeaurora.org>
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>
Link: https://lore.kernel.org/r/1561472086-23360-1-git-send-email-neeraju@codeaurora.org


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Git-commit: 4b7618fdc7e6ac2832842df0cb512ebb067db977
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl.git


[neeraju@codeaurora: Resolve trivial merge conflicts]
[neeraju@codeaurora: Update to use functions/apis in msm-4.19 kernel.]
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>