drm/panthor: Remove dead VM flushing code

Commit ec62d37d2c0d("drm/panthor: Fix the fast-reset logic") did away
with the only reference to panthor_vm_flush_all(), so let's get rid
of the orphaned definition.

Signed-off-by: Adrián Larumbe <[e-mail]>
Reviewed-by: Liviu Dudau <[e-mail]>
Reviewed-by: Steven Price <[e-mail]>
Signed-off-by: Steven Price <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/gpu/drm/panthor/panthor_mmu.c

···
 	return ret;
 }
 
-/**
- * panthor_vm_flush_all() - Flush L2 caches for the entirety of a VM's AS
- * @vm: VM whose cache to flush
- *
- * Return: 0 on success, a negative error code if flush failed.
- */
-int panthor_vm_flush_all(struct panthor_vm *vm)
-{
-	return panthor_vm_flush_range(vm, vm->base.mm_start, vm->base.mm_range);
-}
-
 static int panthor_vm_unmap_pages(struct panthor_vm *vm, u64 iova, u64 size)
 {
 	struct panthor_device *ptdev = vm->ptdev;

drivers/gpu/drm/panthor/panthor_mmu.h

···
 void panthor_vm_idle(struct panthor_vm *vm);
 u32 panthor_vm_page_size(struct panthor_vm *vm);
 int panthor_vm_as(struct panthor_vm *vm);
-int panthor_vm_flush_all(struct panthor_vm *vm);
 
 struct panthor_heap_pool *
 panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create);