ath9k: make const array reg_hole_list static, reduces object code size

Don't populate the read-only array reg_hole_list on the stack, instead make
it static.  Makes the object code smaller by over 200 bytes:

Before:
   text	   data	    bss	    dec	    hex	filename
  57518	  15248	      0	  72766	  11c3e	debug.o

After:
   text	   data	    bss	    dec	    hex	filename
  57218	  15344	      0	  72562	  11b72	debug.o
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NKalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath9k/debug.c

@@ -916,7 +916,7 @@ static int open_file_regdump(struct inode *inode, struct file *file)
 	u8 *buf;
 	int i, j = 0;
 	unsigned long num_regs, regdump_len, max_reg_offset;
-	const struct reg_hole {
+	static const struct reg_hole {
 		u32 start;
 		u32 end;
 	} reg_hole_list[] = {