testsuite/arm: Fix scan-assembler-times in pr96770.c with movt/movw

testsuite/arm: Fix scan-assembler-times in pr96770.c with movt/movw

The previous change to this testcase missed the fact that the data may
be accessed via an anchor, depending on the optimization level,
leading to false failures.

This patch restricts matching to upper16:lower16 followed by
non-spaces, followed by +4 (in f4) or +320 (in f5).

Using '.*' instead of '[^ \]' would match accross the whole assembly
file, which is not what we want, hence the limitation with spaces.

2021-04-16  Christophe Lyon  <christophe.lyon@linaro.org>

	gcc/testsuite/
	PR target/96770
	* gcc.target/arm/pure-code/pr96770.c: Fix scan-assembler-times
	with movt/movw.