HID: sony: Correct Sixaxis battery reporting

The battery_charging and cable_state flags were backwards on the Sixaxis.
The low bit of report byte 30 is 0 when charging and 1 when not.
Bit 5 of byte 31 is 0 when a USB cable is connected and 1 when not.

Signed-off-by: Frank Praznik <frank.praznik@oh.rr.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>