core: bugfix mobj_virt

Prior to this patch is mobj_virt using mobj_phys_ops instead of the
expected mobj_virt_ops. This patch fixes mobj_virt to use mobj_virt_ops.

Fixes: 0dcfa56 ("core: introduce MOBJ abstraction")
Reviewed-by: Jerome Forissier <jerome.forissier@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

core/arch/arm/mm/mobj.c

@@ -194,7 +194,7 @@ static void mobj_virt_assert_type(struct mobj *mobj __maybe_unused)
 	assert(mobj->ops == &mobj_virt_ops);
 }
 
-struct mobj mobj_virt = { .ops = &mobj_phys_ops, .size = SIZE_MAX };
+struct mobj mobj_virt = { .ops = &mobj_virt_ops, .size = SIZE_MAX };
 
 /*
  * mobj_mm implementation