Add a command to reset battery status after replacement

The SPI protocol used is very simple, basically, it receives the address and returns back the value on that address. In order to also allow some commands that triggers one action we can use the same mechanism an access over the map, then the address is interpreted as a command. If the command is supported a 0 is returned, otherwise a SPI_DUMMY_BYTE is returned.

A new command (129) is implemented to allow to reset battery status after replacement.

Signed-off-by: Enric Balletbo i Serra enric.balletbo@collabora.com