mesa/main: add missing include in glformats.h

This header uses uint32_t without including stdint.h. This worked fine
by accident until a new c-source started including it.

Fixes: 1bf539b3a21 ("mesa: Clamp some depth values in glClearBufferfv")
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7637>
(cherry picked from commit 2410def98fa688aa009b42de3224e12e5ddbaff3)
2 files changed