board: ti: j721e: Enable support for reading EEPROM at next alternate address

J721E EVM has EEPROM populated at 0x50. J721E SK has EEPROM populated
at next address 0x51 in order to be compatible with RPi. So start
looking for TI specific EEPROM at 0x50, if not found look for EEPROM at
0x51.

Signed-off-by: Sinthu Raja <sinthu.raja@ti.com>