drm/i915/guc: Add debug capture of GuC exception

drm/i915/guc: Add debug capture of GuC exception

Detect GuC firmware load failure due to an exception during execution
in GuC firmware. Output the GuC EIP where exception occurred to dmesg
for GuC debug information.

v2: correct typos, change debug message and error code returned for
GuC exception (Michal)

Signed-off-by: Robert M. Fosha <robert.m.fosha@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190625164107.21512-1-robert.m.fosha@intel.com