drm/i915: Migrate platform-dependent mock hugepage selftests to live

Convert the igt_mock_ppgtt_huge_fill and igt_mock_ppgtt_64K mock selftests
into live selftests as their requirements have recently become
platform-dependent. Additionally, apply necessary platform dependency
checks to these tests.

v8:
- handle properly 64K and 2M pages
v9:
- do not expect 64K pages if 2M are present
- fix hex printing
- obey commit message line limit

Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Co-developed-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230425-hugepage-migrate-v8-1-7868d54eaa27@intel.com