gallium/util: add missing u_debug include
gallium/util: add missing u_debug include

Needed for assert.
Fixes build on BE archs with -Werror=implicit-function-declaration.

In file included from
../../../../../src/gallium/auxiliary/draw/draw_fs.c:30:0:
../../../../../src/gallium/auxiliary/util/u_math.h: In function
'util_memcpy_cpu_to_le32':
../../../../../src/gallium/auxiliary/util/u_math.h:810:4: error:
implicit declaration of function 'assert'
[-Werror=implicit-function-declaration]
    assert(n % 4 == 0);
        ^

Cc: "10.3" <59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org>
Signed-off-by: Andreas Boll <041cac00e0cb793452cecf5c52a77db13d069cf3@gmail.com>
Reviewed-by: Marek Olšák <8c7344a1abdb103e79ecfd488098373070c3c70e@amd.com>

tokyovigilante/glsl-optimizer,jbarczak/glsl-optimizer,mcanthony/glsl-optimizer,zeux/glsl-optimizer,djreep81/glsl-optimizer,jbarczak/glsl-optimizer,bkaradzic/glsl-optimizer,zeux/glsl-optimizer,mcanthony/glsl-optimizer,dellis1972/glsl-optimizer,jbarczak/glsl-optimizer,djreep81/glsl-optimizer,dellis1972/glsl-optimizer,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,djreep81/glsl-optimizer,tokyovigilante/glsl-optimizer,wolf96/glsl-optimizer,mcanthony/glsl-optimizer,dellis1972/glsl-optimizer,benaadams/glsl-optimizer,bkaradzic/glsl-optimizer,metora/MesaGLSLCompiler,bkaradzic/glsl-optimizer,metora/MesaGLSLCompiler,benaadams/glsl-optimizer,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,bkaradzic/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,jbarczak/glsl-optimizer,zz85/glsl-optimizer,djreep81/glsl-optimizer,mcanthony/glsl-optimizer,zeux/glsl-optimizer,tokyovigilante/glsl-optimizer,jbarczak/glsl-optimizer,zz85/glsl-optimizer,zeux/glsl-optimizer,wolf96/glsl-optimizer,djreep81/glsl-optimizer,tokyovigilante/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,mcanthony/glsl-optimizer,zeux/glsl-optimizer,zz85/glsl-optimizer,dellis1972/glsl-optimizer,metora/MesaGLSLCompiler,bkaradzic/glsl-optimizer,benaadams/glsl-optimizer,benaadams/glsl-optimizer,benaadams/glsl-optimizer,wolf96/glsl-optimizer