core: GP_Pixel.gen.h.t: Add #define GP_PIXEL_foo
core: GP_Pixel.gen.h.t: Add #define GP_PIXEL_foo

So that we can use:

 #ifdef GP_PIXEL_RGBA5551
	...
 #endif

for less common pixel types.

Signed-off-by: Cyril Hrubis <b1e90efd3b808b8e0bcf2a9a55fd8b9a779bfd81@ucw.cz>

gfxprim/gfxprim,gfxprim/gfxprim,gfxprim/gfxprim,gfxprim/gfxprim,gfxprim/gfxprim