mtest2make: add dependencies to the "speed-qualified" suite

mtest2make: add dependencies to the "speed-qualified" suite

Thorough tests may have more dependencies than faster ones.
Dependencies are now looked up based on the suites being
executed, not on the suites passed as goals to the makefile.
Therefore, it is possible to limit dependencies to the
speeds that need them.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>