The restriction to 4G was strictly to work around 64b math bug in some
versions of SQE firmware.  This appears to be fixed in a650+ SQE fw, so
allow a larger address space size on these devices.

Also, add a modparam override for debugging and igt.

v2: Send the right version of the patch (ie. the one that actually
    compiles)
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/487601/
Link: https://lore.kernel.org/r/20220529180428.2577832-1-robdclark@gmail.com