drm/i915: Remove misleading debug message

haswell_write_eld() is also used on broadwell, so let's not explicitely
mention Haswell. The rest of the function has plenty of debug output
which will print the function name, so we know where we are anyway.

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