drm: ast: fix double __iomem sparse warning

drm: ast: fix double __iomem sparse warning

sparse complains about having 2 "__iomem" attributes on the same line
where only one is needed since the first one applies to everything
up to the ending ';'.
However, to make it clear(er) that both of these pointers are
"__iomem", use separate lines for them.

../drivers/gpu/drm/ast/ast_cursor.c:256:26: CK: warning: duplicate [noderef]
../drivers/gpu/drm/ast/ast_cursor.c:256:26: CK: error: multiple address space given: __iomem & __iomem

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dave Airlie <airlied@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/a8185578-a69a-16b0-6fdf-f4e46bc4f61f@infradead.org