Remove unused function definitions and declarations from ewah
bitmap subsystem.
* ds/ewah-cleanup:
ewah: delete unused 'rlwit_discharge_empty()'
ewah: drop ewah_serialize_native function
ewah: drop ewah_deserialize function
ewah_io: delete unused 'ewah_serialize()'
ewah_bitmap: delete unused 'ewah_or()'
ewah_bitmap: delete unused 'ewah_not()'
ewah_bitmap: delete unused 'ewah_and_not()'
ewah_bitmap: delete unused 'ewah_and()'
ewah/bitmap.c: delete unused 'bitmap_each_bit()'
ewah/bitmap.c: delete unused 'bitmap_clear()'