r8152: support request_firmware for RTL8153

This patch supports loading additional firmware file through
request_firmware().

A firmware file may include a header followed by several blocks
which have different types of firmware. Currently, the supported
types are RTL_FW_END, RTL_FW_PLA, and RTL_FW_USB.

The firmware is used to fix some compatible or hardware issues. For
example, the device couldn't be found after rebooting several times.

The supported chips are
	RTL_VER_04 (rtl8153a-2.fw)
	RTL_VER_05 (rtl8153a-3.fw)
	RTL_VER_06 (rtl8153a-4.fw)
	RTL_VER_09 (rtl8153b-2.fw)

Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>