qcom: spmi-wled: Add support for WLED5 peripheral in PM855L

Currently, WLED driver supports only WLED4 peripherals that is
present on pmi8998 and pm660L. Add support for WLED5 peripheral
that is present on PM855L.

PM855L WLED supports the following.
- Two modulators and each sink can use any of the modulator
- Multiple CABC selection options
- Multiple brightness width selection (12 bits to 15 bits)

Change-Id: I9a5291033a84c987f25abef5e1b425ed27ddd6d8
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>