Input: omap4-keypad - SYSCONFIG register configuration

Remove SYSCONFIG register configuration, omap hwmod framework will
use internal API to modify as required.

Other minor updates:

- Change a variable name from DEF to VAL, this represents a value
- Break line width to 80 characters

Signed-off-by: Abraham Arce <x0066660@ti.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>