moxtet: remove unused moxtet_type declaration

For some reason, moxtet_type was defined in moxtet.h, but never actually
used.  Looks like a left-over from the original commit that was
exporting the moxtet bus type, but that wasn't needed, and it was a
different variable name, so no one noticed this one dangling around.

Cc: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/2023121937-pants-heroics-17c1@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: gregkh

include/linux/moxtet.h

@@ -35,8 +35,6 @@ enum turris_mox_module_id {
 
 #define MOXTET_NIRQS	16
 
-extern struct bus_type moxtet_type;
-
 struct moxtet {
 	struct device			*dev;
 	struct mutex			lock;