egl: implement EGL_EXT_protected_surface support

Reviewed-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5096>

include/GL/internal/dri_interface.h

@@ -1367,6 +1367,7 @@ struct __DRIdri2ExtensionRec {
  * could be read after a flush."
  */
 #define __DRI_IMAGE_USE_BACKBUFFER      0x0010
+#define __DRI_IMAGE_USE_PROTECTED       0x0020
 
 
 #define __DRI_IMAGE_TRANSFER_READ            0x1
@@ -1932,6 +1933,8 @@ typedef struct __DRIDriverVtableExtensionRec {
 #define   __DRI2_RENDERER_HAS_CONTEXT_PRIORITY_MEDIUM         (1 << 1)
 #define   __DRI2_RENDERER_HAS_CONTEXT_PRIORITY_HIGH           (1 << 2)
 
+#define __DRI2_RENDERER_HAS_PROTECTED_CONTENT                 0x000e
+
 typedef struct __DRI2rendererQueryExtensionRec __DRI2rendererQueryExtension;
 struct __DRI2rendererQueryExtensionRec {
    __DRIextension base;