This breaks the debugfs portions of the AB5500 driver into its own
file. Split off a _raw function to access registers since we don't
want to expose a generically named function globally. Move all
required data structures to a shared ab5500-core.h file.

Cc: Mattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The analog baseband chip ab5500 is a multi functional chip
containing regulators, charging, gpio, USB and accessory detect.
It also contain various multimedia functionalities like digital
encoder and audio codec.
The core driver added with this patch provides register access via
i2c via PRCMU. Event handling implemented as irq_chip will come in
future patches since it depends on PRCMU functionality not yet
implemented.
Signed-off-by: NMattias Wallin <mattias.wallin@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>