Rather than pass in the soft-masking and KVM tests via macro that is
passed to another macro to expand it, switch to usig gas macros and
conditionally expand the soft-masking and KVM tests.

The system reset with its idle test is open coded as it is a one-off.

No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>