drm/i915/selftest: Make sure to init i915_ggtt_view in igt_vma_rotate_remap()

drm/i915/selftest: Make sure to init i915_ggtt_view in igt_vma_rotate_remap()

This probably doesn't cause an issue, since the code checks the view
type dependent size of the views before comparing them, but let's follow
the practice to bzero the whole struct when initializing it.

v2: Use {} instead of { } struct intializer. (Ville)

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210325214808.2071517-6-imre.deak@intel.com