Update Freescale sys_eeprom.c to handle CCID formats

Update the sys_eeprom.c file to handle both NXID and CCID EEPROM formats.  The
NXID format replaces the older CCID format, but it's important to support both
since most boards out there still use the CCID format.  This change is in
preparation for using one file to handle both formats.  This will also unify
EEPROM support for all Freescale 85xx and 86xx boards.

Also update the 86xx board header files to use the standard CFG_I2C_EEPROM_ADDR
instead of ID_EEPROM_ADDR.

Signed-off-by: Timur Tabi <timur@freescale.com>