drm/i915/gvt: do not use implict dev_priv in DSPSURF_TO_PIPE()

Do not rely on having dev_priv local variable, pass it to the macro.

Cc: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: Zhi Wang <zhi.wang.linux@gmail.com>
Cc: intel-gvt-dev@lists.freedesktop.org
Reviewed-by: Zhi Wang <zhiwang@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/2ff78ebd0dc84178f5feacee7ef2a6cb4132b9ae.1717773890.git.jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>