pcf50633_charger: Remove unused mbc_set_status function

The 'pcf50633_mbc_set_status' function is unused, so remove it.

Signed-off-by: Balaji Rao <balajirrao@openmoko.org>
Cc: Andy Green <andy@openmoko.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>