gallium: add PIPE_MAX_SHADER_IMAGES and image read/write defines.

This just brings over some defines from the gallium codebase.

Co-authors: Gurchetan Singh <gurchetansingh@chromium.org>

Reviewed-By: Gert Wollny <gert.wollny@collabora.com>

src/gallium/include/pipe/p_defines.h

@@ -484,6 +484,14 @@ enum pipe_flush_flags {
 
 #define PIPE_TIMEOUT_INFINITE 0xffffffffffffffffull
 
+/**
+ * pipe_image_view access flags.
+ */
+#define PIPE_IMAGE_ACCESS_READ       (1 << 0)
+#define PIPE_IMAGE_ACCESS_WRITE      (1 << 1)
+#define PIPE_IMAGE_ACCESS_READ_WRITE (PIPE_IMAGE_ACCESS_READ | \
+                                      PIPE_IMAGE_ACCESS_WRITE)
+
 /**
  * Implementation capabilities/limits which are queried through
  * pipe_screen::get_param()

src/gallium/include/pipe/p_state.h

@@ -62,6 +62,7 @@ extern "C" {
 #define PIPE_MAX_SHADER_OUTPUTS   48 /* 32 GENERICs + POS, PSIZE, FOG, etc. */
 #define PIPE_MAX_SHADER_SAMPLER_VIEWS 32
 #define PIPE_MAX_SHADER_BUFFERS   32
+#define PIPE_MAX_SHADER_IMAGES    32
 #define PIPE_MAX_TEXTURE_LEVELS   16
 #define PIPE_MAX_SO_BUFFERS        4
 #define PIPE_MAX_SO_OUTPUTS       64