arm: [MVE intrinsics] remove useless call_properties implementations.

vstrq_impl derives from store_truncating and vldrq_impl derives from
load_extending which both implement call_properties.

No need to re-implement them in the derived classes.

gcc/ChangeLog:

	* config/arm/arm-mve-builtins-base.cc (vstrq_impl): Remove
	call_properties.
	(vldrq_impl): Likewise.