python: Fix AddrRange legacy ParamValue wrapper

python: Fix AddrRange legacy ParamValue wrapper

This change fixes a bug that would manifest if a user would
instantiate an AddrRange ParamValue using the kwargs 'intlvBits' and
'intlvHighBit' without specifying the optional 'xorHighBit'.

Change-Id: I2091c432234df9cf907d52af6ba7f0cadd8c37a8
Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/19248
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Tested-by: kokoro <noreply+kokoro@google.com>