Simplify runtime request creation by storing the context we need to use
during initialisation. This allows us to remove one more hardcoded
engine lookup.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190704200455.14870-1-chris@chris-wilson.co.uk