MAINTAINERS: wifi: remove Kalle

I'm stepping down as wireless driver maintainer. Johannes kindly voluntereed to
be the "custodian"[1] for the drivers until a better solution is found.

Link: https://lore.kernel.org/all/[email protected]/ [1]
Signed-off-by: Kalle Valo <[email protected]>
Link: https://patch.msgid.link/[email protected]

Author: Kalle Valo

MAINTAINERS

@@ -16341,7 +16341,7 @@ X:	drivers/net/can/
 X:	drivers/net/wireless/
 
 NETWORKING DRIVERS (WIRELESS)
-M:	Kalle Valo <[email protected]>
+M:	Johannes Berg <[email protected]>
 L:	[email protected]
 S:	Maintained
 W:	https://wireless.wiki.kernel.org/