Add support for Maxim's DS4510 I2C device

Initial support for the DS4510, a CPU supervisor with
integrated EEPROM, SRAM, and 4 programmable non-volatile
GPIO pins. The CONFIG_DS4510 define enables support
for the device while the CONFIG_CMD_DS4510 define
enables the ds4510 command. The additional
CONFIG_DS4510_INFO, CONFIG_DS4510_MEM, and
CONFIG_DS4510_RST defines add additional sub-commands
to the ds4510 command when defined.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>