The compute engine handles the same commands the render engine can
(except 3D pipeline), so it makes sense that CCS is more similar to RCS
than non-render engines.

The CCS context state (lrc) is also similar to the render one, so reuse
it. Note that the compute engine has its own CTX_R_PWR_CLK_STATE
register.

In order to avoid having multiple RCS && CCS checks, add the following
engine flag:
 - I915_ENGINE_HAS_RCS_REG_STATE - use the render (larger) reg state ctx.

BSpec: 46260
Original-author: Michel Thierry
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Aravind Iddamsetty <aravind.iddamsetty@intel.com>
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220301231549.1817978-6-matthew.d.roper@intel.com