wl1251: Remove unused wl1251_cmd_*

wl1251_cmd_read_memory() and wl1251_cmd_test() last use was removed in
2009 by
commit f298c282 ("wl1251: remove accidentally added wl1251_netlink.c")

Remove them.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://patch.msgid.link/20250622172804.116396-3-linux@treblig.org


Signed-off-by: Johannes Berg <johannes.berg@intel.com>