power supply: collie_battery: Convert to use dev_pm_ops

This commit fixes the following warnings:

 linux/drivers/power/collie_battery.c:372:2: warning: initialization from
 incompatible pointer type [enabled by default]
 linux/drivers/power/collie_battery.c:372:2: warning: (near initialization
 for 'collie_bat_driver.suspend') [enabled by default]

Referencess:

MFD: ucb1x00-core: convert to use dev_pm_ops
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/include/linux/mfd?id=5a09b7120a965a7d7e8494d0ed509135bbce0118

MFD: mcp-core: remove legacy driver suspend/resume methods
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/include/linux/mfd?id=cf4abfcc0df2985ff6061f74e63b8353f2a1d0bc



Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>