turnip: Add support for VK_VALVE_mutable_descriptor_type

turnip: Add support for VK_VALVE_mutable_descriptor_type

v1.  Hyunjun Ko <zzoon@igalia.com>
- Add to hanlde VK_DESCRIPTOR_POOL_CREATE_HOST_ONLY_BIT_VALVE
- Don't support VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT and
VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER

v2.  Hyunjun Ko <zzoon@igalia.com>
- Fix some indentations and nitpicks.
- Add the extension to features.txt

v3.  Hyunjun Ko <zzoon@igalia.com>
- Remove unnecessary asserts.

Signed-off-by: Eduardo Lima Mitev <elima@igalia.com>
Signed-off-by: Hyunjun Ko <zzoon@igalia.com>
Reviewed-by: Danylo Piliaiev <dpiliaiev@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9322>