ARM: 9121/1: amba: Drop unused functions about APB/AHB devices add

No one use the following functions, kill them.

  amba_aphb_device_add()
  amba_apb_device_add()
  amba_apb_device_add_res()
  amba_ahb_device_add()
  amba_ahb_device_add_res()

Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>