drm/hisilicon/kirin: Allow build with COMPILE_TEST=y

Allow kirin to be built with COMPILE_TEST=y for greater
coverage. Builds fine on x86/x86_64 at least.

Cc: Xinliang Liu <xinliang.liu@linaro.org>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: Xinwei Kong <kong.kongxinwei@hisilicon.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Yongqin Liu <yongqin.liu@linaro.org>
Cc: John Stultz <jstultz@google.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240408170426.9285-12-ville.syrjala@linux.intel.com
Acked-by: John Stultz <jstultz@google.com>