arm: Fix MVE's vcmp vector-scalar patterns [PR107987]

arm: Fix MVE's vcmp vector-scalar patterns [PR107987]

This patch surrounds the scalar operand of the MVE vcmp patterns with a
vec_duplicate to ensure both operands of the comparision operator have the same
(vector) mode.

gcc/ChangeLog:

	PR target/107987
	* config/arm/mve.md (mve_vcmp<mve_cmp_op>q_n_<mode>,
	@mve_vcmp<mve_cmp_op>q_n_f<mode>): Apply vec_duplicate to scalar
	operand.

gcc/testsuite/ChangeLog:

	* gcc.target/arm/mve/pr107987.c: New test.

(cherry picked from commit ed34c3bc3428bce663d42e9eeda10bc0c5d56d5c)