pm2301-charger: Add pm_runtime_resume & pm_runtime_suspend

To optimize the current consumption we use pm_runtime autosuspend
functions which execute the pm_runtime_suspend after a delay of
inactivity on the other hand we use pm_runtime_resume every time
we receive an interruption to wake up the pm2301.

Signed-off-by: M BenZoubeir <mustapha.ben.zoubeir-xsig@stericsson.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>