ARM: dts: msm: correct Focaltech CTP irq flag configuration

Fixed below irq flag issues of Focaltech CTP:
Focaltech CTP firmware generates edge interrupt to MSM, but the
interrupt type in DTSI is level, which will cause CTP interrupt
cannot wake up MSM when system is in deep sleep. Fix this by
setting edge irq flag in DTSI.

For GPIO irq, the irq flag should be specified in "interrupts"
node. Msm_gpio module will only use the lower 8-bit of
"interrupts" node and discards the upper bits. If we specify
0x2002 in "interrupts" node, the upper bits(0x2000) is not used
by msm_gpio, only lower bits(0x2) is used, that means only
lower bits(0x2) should be set in "interrupts" node.

"focaltech,irq-gpio" node is used to specify gpio property,
rather than irq flag. Remove the irq flag setting in this node.

In driver code, specify only "IRQF_ONESHOT". The irq trigger type
is specified by DTSI "interrupts" node. See above.

Change-Id: I4cd8596fb4538b701317f01a6cafaa771041ffdd
Signed-off-by: Mao Li <maol@codeaurora.org>