drivers: mfd: donot clear interrupt status

If there is a fake interrupt SW is clearing interrupt status,
due to this some of the required interrupts are getting cleared.
Remove clearing of status register to avoid this.

CRs-Fixed: 2045773
Change-Id: I38247d69bd49a64731c3ec695d5470f5c591fea6
Signed-off-by: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>