drm/i915/guc: Dump perf_limit_reasons for debug

GuC load takes longer sometimes due to GT frequency not ramping up.
Add perf_limit_reasons to the existing warn print to see if frequency
is being throttled.

v2: Review comments (Ashutosh)

Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230627191336.319381-1-vinay.belgaumkar@intel.com