arm: testsuite: fix some more architecture tests

This fixes a bunch more tests that try to override the default architecture;
some partially used the framework for doing this, others just blindly
added a -march option, which was doomed to cause problems.  In most cases
we can now run these tests regardless of the users testing options and
the base compiler configuration.

gcc/testsuite:

	* lib/target-supports.exp (check_effective_target_arm_arch_FUNC_ok):
	Add test for v7a_arm.
	* gcc.target/arm/pr60650-2.c: Use require-effective-target and
	add-options.
	* gcc.target/arm/pr60657.c: Likewise.
	* gcc.target/arm/pr60663.c: Likewise.
	* gcc.target/arm/pr81863.c: Likewise.
	* gcc.target/arm/pr97969.c: Likewise.
	* gcc.target/arm/pr98931.c: Likewise.
	* gcc.target/arm/tail-long-call.c: Likewise.