bq27x00_battery: Fix bugs introduced with BQ27425 support

commit a66f59ba

    bq27x00_battery: Add support for BQ27425 chip

introduced 2 bugs.

1/ 'chip' was set to BQ27425 unconditionally - breaking support for
   other devices;

2/ BQ27425 does not support cycle count, how the code still tries to
   get the cycle count for BQ27425, and now does it twice for other chips.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Saranya Gopal <saranya.gopal@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Anton Vorontsov <anton@enomsg.org>