input: qpnp-power-on: Add debounce for KPDPWR_N rising edge

On certain PMICs, an unexpected assertion on KPDPWR_DBC may
be seen during falling edge of KPDPWR_N when it is closer
to the rising edge of SLEEP_CLK. This triggers spurious
KPDPWR interrupts. Handle this by adding a debounce in SW
when the first KPDPWR_N falling edge is seen.

The debounce logic is enabled by the DT property
'qcom,kpdpwr-sw-debounce'.

CRs-Fixed: 2032520
Change-Id: I7655c13bda47fa6e2983650d7bec21e52aa91c2f
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>