include/bitfield: Add new bitfield operations

These new operations allow manipulation of bitfields
within a word by using a mask instead of width and
shift values to extract/replace the bitfields.

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@freescale.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: York Sun <yorksun@freescale.com>