staging: ks7010: add enum multicast_filter_type

Driver uses preprocessor directives to define multicast filter
constants. These can be defined using an enumeration type. Doing so
adds to the readability and gives the assists the compiler.

Add enumeration type multicast_filter_type to replace preprocessor
defined constants.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>