overflow: add range_overflows() and range_end_overflows()

overflow: add range_overflows() and range_end_overflows()

Move the range_overflows() and range_end_overflows() along with the _t
variants over from drm/i915 and drm/buddy to overflow.h.

Cc: Kees Cook <kees@kernel.org>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: linux-hardening@vger.kernel.org
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250829174601.2163064-3-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>