powerpc: Record vma->phys_addr in ioremap()

The vmalloc code can track the physical address of a vma, when the
vma is used for ioremap, if set it is displayed in /proc/vmallocinfo.

Because get_vm_area_caller() doesn't know it's being called for
ioremap() it's up to the arch code to set the phys_addr. A bunch
of other arch's do this, I'm not sure why powerpc doesn't?

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/mm/pgtable_64.c

@@ -223,6 +223,8 @@ void __iomem * __ioremap_caller(phys_addr_t addr, unsigned long size,
 					    caller);
 		if (area == NULL)
 			return NULL;
+
+		area->phys_addr = paligned;
 		ret = __ioremap_at(paligned, area->addr, size, flags);
 		if (!ret)
 			vunmap(area->addr);