gl-renderer: support format and modifier queries

EGL_EXT_image_dma_buf_import_modifiers allows querying the formats
and modifiers supported by the platform. expose these to the compositor.

v2:
 - change calloc args (Daniel Stone)
 - check for modifier support before querying formats (Daniel Stone)

Signed-off-by: Varad Gautam <varad.gautam@collabora.com>
Reviewed-by: Daniel Stone <daniels@collabora.com>
diff --git a/shared/weston-egl-ext.h b/shared/weston-egl-ext.h
index f3e6dce..c7a3430 100644
--- a/shared/weston-egl-ext.h
+++ b/shared/weston-egl-ext.h
@@ -125,6 +125,13 @@
 #define EGL_DMA_BUF_PLANE2_PITCH_EXT				0x327A
 #endif
 
+/* Define tokens from EGL_EXT_image_dma_buf_import_modifiers */
+#ifndef EGL_EXT_image_dma_buf_import_modifiers
+#define EGL_EXT_image_dma_buf_import_modifiers 1
+typedef EGLBoolean (EGLAPIENTRYP PFNEGLQUERYDMABUFFORMATSEXTPROC) (EGLDisplay dpy, EGLint max_formats, EGLint *formats, EGLint *num_formats);
+typedef EGLBoolean (EGLAPIENTRYP PFNEGLQUERYDMABUFMODIFIERSEXTPROC) (EGLDisplay dpy, EGLint format, EGLint max_modifiers, EGLuint64KHR *modifiers, EGLBoolean *external_only, EGLint *num_modifiers);
+#endif
+
 #ifndef EGL_EXT_swap_buffers_with_damage
 #define EGL_EXT_swap_buffers_with_damage 1
 typedef EGLBoolean (EGLAPIENTRYP PFNEGLSWAPBUFFERSWITHDAMAGEEXTPROC) (EGLDisplay dpy, EGLSurface surface, EGLint *rects, EGLint n_rects);