Arm: MVE: Add missing complex mul iterators

Seems when I split the patch I forgot to include these into the rot iterator..
The uncommitted hunks were still in my local tree so didn't notice.

gcc/ChangeLog:

	* config/arm/iterators.md (rot): Add UNSPEC_VCMUL, UNSPEC_VCMUL90,
	UNSPEC_VCMUL180, UNSPEC_VCMUL270.

gcc/config/arm/iterators.md

@@ -1177,6 +1177,10 @@
 
 (define_int_attr rot [(UNSPEC_VCADD90 "90")
 		      (UNSPEC_VCADD270 "270")
+		      (UNSPEC_VCMUL "0")
+		      (UNSPEC_VCMUL90 "90")
+		      (UNSPEC_VCMUL180 "180")
+		      (UNSPEC_VCMUL270 "270")
 		      (UNSPEC_VCMLA "0")
 		      (UNSPEC_VCMLA90 "90")
 		      (UNSPEC_VCMLA180 "180")