leds: qpnp-wled: Fix configuration for AMOLED mode

Some registers are configured incorrectly for AMOLED mode in WLED
peripheral. Fix them based on the hardware documentation.

Change-Id: If021423653b94f1bcc97cdb50b7067af24bcef61
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>