drm/panfrost: Constify argument to has_hw_issue

Logically, this function is free of side effects, so any pointers it
takes should be const. Needed to avoid a warning in the next patch.

Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220525145754.25866-4-alyssa.rosenzweig@collabora.com