isdn: Fix typo in isdn drivers

Fix spelling typo in debug messages within drivers/isdn.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/isdn/hisax/amd7930_fn.c

@@ -628,7 +628,7 @@ Amd7930_l1hw(struct PStack *st, int pr, void *arg)
 		if ((cs->dc.amd7930.ph_state == 8)) {
 			/* b-channels off, PH-AR cleared
 			 * change to F3 */
-			Amd7930_ph_command(cs, 0x20, "HW_RESET REQEST"); //LMR1 bit 5
+			Amd7930_ph_command(cs, 0x20, "HW_RESET REQUEST"); //LMR1 bit 5
 			spin_unlock_irqrestore(&cs->lock, flags);
 		} else {
 			Amd7930_ph_command(cs, 0x40, "HW_RESET REQUEST");