arm: [MVE intrinsics] add binary_move_narrow and binary_move_narrow_unsigned shapes

This patch adds the binary_move_narrow and binary_move_narrow_unsigned
shapes descriptions.

2022-09-08  Christophe Lyon  <christophe.lyon@arm.com>

	gcc/
	* config/arm/arm-mve-builtins-shapes.cc (binary_move_narrow): New.
	(binary_move_narrow_unsigned): New.
	* config/arm/arm-mve-builtins-shapes.h (binary_move_narrow): New.
	(binary_move_narrow_unsigned): New.