drm/msm: msm_iommu.c: fix all kernel-doc warnings

Correct or add kernel-doc comments to eliminate all warnings:

Warning: ../drivers/gpu/drm/msm/msm_iommu.c:381 expecting prototype for
 alloc_pt(). Prototype was for msm_iommu_pagetable_alloc_pt() instead
Warning: ../drivers/gpu/drm/msm/msm_iommu.c:426 expecting prototype for
 free_pt(). Prototype was for msm_iommu_pagetable_free_pt() instead

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/695675/
Link: https://lore.kernel.org/r/20251219184638.1813181-20-rdunlap@infradead.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Author: rddunlap

drivers/gpu/drm/msm/msm_iommu.c

@@ -364,7 +364,7 @@ msm_iommu_pagetable_prealloc_cleanup(struct msm_mmu *mmu, struct msm_mmu_preallo
 }
 
 /**
- * alloc_pt() - Custom page table allocator
+ * msm_iommu_pagetable_alloc_pt() - Custom page table allocator
  * @cookie: Cookie passed at page table allocation time.
  * @size: Size of the page table. This size should be fixed,
  * and determined at creation time based on the granule size.
@@ -416,7 +416,7 @@ msm_iommu_pagetable_alloc_pt(void *cookie, size_t size, gfp_t gfp)
 
 
 /**
- * free_pt() - Custom page table free function
+ * msm_iommu_pagetable_free_pt() - Custom page table free function
  * @cookie: Cookie passed at page table allocation time.
  * @data: Page table to free.
  * @size: Size of the page table. This size should be fixed,