LibGfx: Use PkgConfig to find libdrm

On FreeBSD the libdrm headers are not in a standard location so this
makes the include more portable.

Author: cqundefine

Libraries/LibGfx/CMakeLists.txt

@@ -173,4 +173,9 @@ endif()
 
 if (HAS_VULKAN)
     target_link_libraries(LibCore PUBLIC Vulkan::Vulkan Vulkan::Headers)
+
+    if ((LINUX AND NOT ANDROID) OR CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+        pkg_check_modules(LibDRM REQUIRED libdrm)
+        target_include_directories(LibGfx PUBLIC ${LibDRM_INCLUDE_DIRS})
+    endif()
 endif()