mfd: Using MFD_xx prefix for symbols ...

This patch provides rename MFD-related symbols for using MFD-prefix.
Additionally, sorting mfd/Kconfig and mfd/Makefile records.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

twl-core: abstract twl4030 and add twlcore driver ...

Add a general twl device driver twlcore to call i2c send/write
functions.
Abstract twl4030 to call twlcore functions.

Fixed some code-styling issues pointed out by checkpatch.

Signed-off-by: Alexander Aring <a.aring@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>