pm2301-charger: Force main charger detect

Force main charger detect in turn on status.

Signed-off-by: Rajkumar Kasirajan <rajkumar.kasirajan@stericsson.com>
Signed-off-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>
Tested-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>