input: qpnp-power-on: Fix the argument data-type for regmap_bulk_read

regmap_bulk_read internally uses the data-type supported by the device
which is 8-bits for SPMI. Hence, its expected the argument should be
of right data-type (u8) for the data to be read correctly.

Change-Id: Ie14b745f7db625f399ac5f79b3467a1654ea4a22
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>