accel/amdxdna: Fix memory leak in amdxdna_iommu_alloc()

accel/amdxdna: Fix memory leak in amdxdna_iommu_alloc()

In amdxdna_iommu_alloc(), if iommu_map() fails after successfully
allocating both iova and cpu_addr, the code jumps to free_iova
which only frees the iova, leaking the allocated pages.

Fixes: ece3e8980907 ("accel/amdxdna: Allow forcing IOVA-based DMA via module parameter")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://patch.msgid.link/20260416-amdxdna-v1-1-30c13008365c@gmail.com