mfd: twl: fix twl4030 rename for remaining driver, board files

Recent drivers/mfd/twl4030* renames to twl broke compile for
various boards as the series was missing a patch to change
the board-*.c files.

This patch renames include twl4030.h to include twl.h
and also renames twl4030_i2c_ routines.

Signed-off-by: Balaji T K <balajitk@ti.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>