ACPI: AMBA: Fix resource name in /proc/iomem

In function amba_handler_attach(), dev->res.name is initialized by
amba_device_alloc. But when address_found is false, dev->res.name is
assigned to null value, which leads to wrong resource name display in
/proc/iomem, "<BAD>" is seen for those resources.

Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>