Support i.MX6SLL OTP.
There are 4 works in bank7/bank8.
When read, use address offset.
When prog, use bank/index, note that bank7/bank8 we treat
them a single bank when prog.
Tested GP41 and GP31 read/write on eng sample chip.
Signed-off-by: Peng Fan <peng.fan@nxp.com>
(cherry picked from commit f8698b66fc)