python: Add missing operators to NumericParamValue

Add missing operators to NumericParamValue and ensure that they are
able to work on the underlying value if the right hand side is a
param.

Change-Id: I2bd86662aee9891bbd89aed7ebe20b827b5528bd
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/16001
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
1 file changed