ANDROID: GKI: add missing exports for cam_smmu_api.ko

The following symbols are exported:
 - iommu_dma_enable_best_fit_algo
 - iommu_dma_reserve_iova

Signed-off-by: CY Tseng <cytseng@google.com>
Bug: 156262756
Test: compile
Change-Id: I6127d076b49a8a81f0c67724d531ed0507eea8a5
(cherry picked from commit 9dcd3e2c5c99c9cb5ce225192ca8cdafb91bfbe8)
Signed-off-by: Will McVicker <willmcvicker@google.com>