msm: camera: sensor: change loop index to int type

Loop index as 8 bit type causes infinite loop when iteration
is greater than 256. Change it to int and increase macro
I2C_SEQ_REG_DATA_MAX to support larger data burst.

Change-Id: I3aa0c60ca828ce31fa287d15e61f6cf476a0f2c5
Signed-off-by: Xu Han <hanxu@codeaurora.org>