power: pm8921-charger: Make charger removal detection workaround optional

On some platforms such as MPQ8064 the charger removal detection
workarounds - reverse boost fix and OVP FET stuck do not work
as expected as the SMBC module is disconnected from USBout. On
these targets the USB interface is not used for charging but merely
to indicate the USB driver of the insertion/removal.

Add a platform data variable to make this optional and enable
the same for MPQ8064.

Change-Id: I3fca1b357f8fc280483302f72ffbc61fb50109a7
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>