Asoc: wcd9xxx: Avoid unnecessary dispatch of mechanical interrupts

Interrupt number for WCD9306_IRQ_MBHC_JACK_SWITCH and
WCD9320_IRQ_EAR_PA_STARTUP is same due to this single interrupt is
dispatched twice, due to this real interrupts are not getting handled.
To avoid this remove WCD9320_IRQ_EAR_PA_STARTUP from interrupt table.

CRs-Fixed: 589453
Change-Id: Id1945bb6399bc9b3f991ffc587b83ca02dd9647d
Signed-off-by: Yeleswarapu, Nagaradhesh <nagaradh@codeaurora.org>