csky/vdso: Remove arch_vma_name()

All callers of arch_vma_name() also get the name via vm_ops, which for
these VMAs will use the name from 'struct vma_special_mapping'.
Therefore the custom implementation is unnecessary and can be removed in
favor of the default implementation from kernel/signal.c.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-2-b64f0842d512@linutronix.de

arch/csky/kernel/vdso.c

@@ -82,10 +82,3 @@ end:
 	mmap_write_unlock(mm);
 	return ret;
 }
-
-const char *arch_vma_name(struct vm_area_struct *vma)
-{
-	if (vma->vm_mm && (vma->vm_start == (long)vma->vm_mm->context.vdso))
-		return "[vdso]";
-	return NULL;
-}