wifi: ipw2x00: Remove some unused functions

wifi: ipw2x00: Remove some unused functions

Functions write_nic_auto_inc_address() and write_nic_dword_auto_inc() are
defined in the ipw2100.c file, but not called elsewhere, so remove these
unused functions.

drivers/net/wireless/intel/ipw2x00/ipw2100.c:427:20: warning: unused function 'write_nic_dword_auto_inc'.

Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3285
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20221129062407.83157-1-jiapeng.chong@linux.alibaba.com