staging: slicoss: dont use a structure but offsets for register accesses

Use the new register accessors that use offsets instead of the slic_regs
structure to read/write registers. Since not longer needed remove the
structure completley.

Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>