msm8974: mhl_sii8334: init chip on discovery

MHL driver initializes the chip in probe and enables
irq. These operations are postponed until they're
required. This prevents any interrupts from
being triggered even when there is no real
communication from hardware. Do not enable
irq wake in suspend before the first discovery
has completed. This ensures wake irq occurs only on
an irq that has been previously allocated.

CRs-Fixed: 509337
Change-Id: Ifa5c66cfe2fb732d2f8e34b7473ab9ae07937dc7
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>