drm/i915: Turn DEV_INFO_FLAGS into a foreach style macro

DEV_INFO_FOR_FLAG() now takes 2 parameters:
  • A function to apply to the flag
  • A separator

This will allow us to use the macro twice in the DRM_DEBUG_DRIVER() call
of i915_dump_device_info().

v2: Fix a typo in the subject (Jani Nikula)
v3: Undef the helper macros (Jani Nikula, Daniel vetter)

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>