adv7481: Add support for block write

Add support for block i2c write to adv7481 to reduce
write latency and hence improve boot KPI.

Suggested-by: Resmi Rajendran <resmir@qti.qualcomm.com>
Signed-off-by: Jaiju Yesudasan <cjaijuy@codeaurora.org>
Change-Id: I98de976793f47a4a65cf818ee1d919fe3d6200a3