aarch64: testsuite: remove macro expansion messages from expected error output

aarch64: testsuite: remove macro expansion messages from expected error output

gas generates an information diagnostic message for every context
invoking a macro and generating a warning or error message.
For the specific case of sysreg tests, this pollutes the expected
error output for no benefit in term of test debug or testing coverage.

This patch aims at stopping such diagnostic messages to be generated
for the failure tests by providing --no-info flag to gas.
It also removed from the expected outputs the information messages
related to macro expansions.