phy: Add usb phy support for hi3660 Soc of Hisilicon

phy: Add usb phy support for hi3660 Soc of Hisilicon

This driver handles usb phy power on and shutdown for hi3660 Soc of
Hisilicon.

Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Pengcheng Li <lpc.li@hisilicon.com>
Cc: Jianguo Sun <sunjianguo1@huawei.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Jiancheng Xue <xuejiancheng@hisilicon.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Binghui Wang <wangbinghui@hisilicon.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Yu Chen <chenyu56@huawei.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>