bd_address: Return bdaddr in patchram's format

This patch is based on rmcc's patch applied a while ago in drivers/hub/bd_address.c, but instead it should be applied in drivers/misc/bd_address.c, which is the one getting compiled.

Currently the bluetooth address is exported to sysfs (/sys/devices/platform/bd_address/bdaddr_if) without colons, leading to an undefined bluetooth address FF:00:00:00:00:00 in system settings.
By adding colons the address is accepted and correctly set in userspace.
Tested and working on my p970.

Original patch:
https://github.com/CyanogenMod/lge-kernel-sniper/commit/52076572ee89b39deb043e44f73dbddb3033aed7

Change-Id: I996143935d21bb17f11a61e821a748f156963cd8