msm: camera: Improve calibration data parsing

Add checksum verification for calibration data. Regroup calibration data
parsing into a msm_eeprom_memory_block_t struct, so that related
routines
can be reused to read other data later.

Change-Id: Ib58134b6a6c6111d7d39352d1e8bae4a4fdbda5c
Signed-off-by: Sreesudhan Ramakrish Ramkumar <srramku@codeaurora.org>