ARM: dts: msm: Add interrupts to flash-led device for pmicobalt

Add the all-ramp-up-done and all-ramp-down-done interrupts
to the flash-led device for pmicobalt. These interrupts will
be used to notify the flash-led clients when all leds have
completed ramping up or down after the flash is triggered.

CRs-Fixed: 921325
Change-Id: I39a6ba34e43dab8035bf232d0e640e72d7a34575
Signed-off-by: Devesh Jhunjhunwala <deveshj@codeaurora.org>