i965: Use util_next_power_of_two() for brw_get_scratch_size()

This function computes the next power of two, but at least 1024. We can
do that by bitwise or'ing in 1023 and calling util_next_power_of_two().

We use brw_get_scratch_size() from the compiler so we need it out of
brw_program.c. We could move it to brw_shader.cpp, but let's make it a
small inline function instead.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Signed-off-by: Kristian Høgsberg Kristensen <krh@bitplanet.net>

src/mesa/drivers/dri/i965/brw_context.h

@@ -1723,7 +1723,12 @@ void brw_validate_textures( struct brw_context *brw );
  */
 void brwInitFragProgFuncs( struct dd_function_table *functions );
 
-int brw_get_scratch_size(int size);
+/* Per-thread scratch space is a power-of-two multiple of 1KB. */
+static inline int
+brw_get_scratch_size(int size)
+{
+   return util_next_power_of_two(size | 1023);
+}
 void brw_get_scratch_bo(struct brw_context *brw,
 			drm_intel_bo **scratch_bo, int size);
 void brw_init_shader_time(struct brw_context *brw);

src/mesa/drivers/dri/i965/brw_program.c

@@ -242,18 +242,6 @@ brw_add_texrect_params(struct gl_program *prog)
    }
 }
 
-/* Per-thread scratch space is a power-of-two multiple of 1KB. */
-int
-brw_get_scratch_size(int size)
-{
-   int i;
-
-   for (i = 1024; i < size; i *= 2)
-      ;
-
-   return i;
-}
-
 void
 brw_get_scratch_bo(struct brw_context *brw,
 		   drm_intel_bo **scratch_bo, int size)