media: cx23885: Remove unused netup_eeprom_write

netup_eeprom_write() was added in 2009 by
commit b45c0551 ("V4L/DVB (10797): Add EEPROM code for NetUP Dual
DVB-S2 CI card.")
but has remained unused.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>