OAM does not work with media C6 enabled on some steppings of MTL.
Disable OAM if we detect that media C6 was enabled in bios.

v2: (Ashutosh)
- Remove drm_notice from the driver load path
- Log a drm_err when opening an OAM stream on affected steppings

v3:
- Initialize the engine group even if mc6 is enabled (Ashutosh)
- Checkpatch fix
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230323225901.3743681-12-umesh.nerlige.ramappa@intel.com