ANDROID: iommu/iova: Fix to use __alloc_and_insert_iova_best_fit

Looks like there was a merge issue when pulling the following upstream
change:
https://lore.kernel.org/lkml/7239ddd532e94a4371289f3be23c66a3@codeaurora.org/



Fix so that it correctly calls __alloc_and_insert_iova_best_fit when
best_fit is set.

Bug: 149544392
Change-Id: I6b9992dedf4991dee088e77767e0dc077758b581
Signed-off-by: Liam Mark <lmark@codeaurora.org>