USB: PHY: JZ4770: Unify code style and simplify code.

1.Modify the macro definition to unify "#define USBPCR_XXXX n"
  into the "#define USBPCR_XXXX (n << USBPCR_XXXX_LSB)" style,
  so as to unify the code style in the "jz4770_phy_init()" and
  simplify the code.
2.Remove unused macro definitions to simplify the code.

Tested-by: 周正 (Zhou Zheng) <sernia.zhou@foxmail.com>
Suggested-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@wanyeetech.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>