drm/vmwgfx: use *_32_bits() macros

Use the upper_32_bits() macro instead of the four line equivalent that
triggers a GCC warning on 32 bits x86:
    drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c: In function 'vmw_cmdbuf_header_submit':
    drivers/gpu/drm/vmwgfx/vmwgfx_cmdbuf.c:297:25: warning: right shift count >= width of type [-Wshift-count-overflow]
       val = (header->handle >> 32);
                             ^

And use the lower_32_bits() macro instead of and-ing with a 32 bits
mask.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1457000770-2317-1-git-send-email-pebolle@tiscali.nl