CHROMIUM: phy: rockchip-typec: enable usb3 host after pipe ready

If we power off the SoC LOGIC rail in S3, we can find that the
Type-C PHY can't initialize correctly after system resume with
error log looked like this:
  phy phy-ff800000.phy.9: phy poweron failed --> -110
  dwc3 fe900000.dwc3: failed to initialize core
  dwc3: probe of fe900000.dwc3 failed with error -110

It's because that the field of usb3tousb2 in GRF_USB3PHY0/1_CON0
is reset to 1 after power off the SoC LOGIC, which means that the
pipe interface is blocked between Tpye-C PHY and usb3 controller.
And after system resume, the rockchip_usb3_phy_power_on() will call
the tcphy_cfg_usb3_to_usb2_only() to clear the usb3tousb2 bit and
enable the usb3 host again. If we clear the usb3tousb2 bit before
pipe ready, it may cause waiting for pipe ready timeout.

Note that the RK3399 TRM suggests that we should keep the whole usb3
controller in reset for the duration of the Type-C PHY initialization.
However, it's hard to assert the reset in the current framework of
reset. And according to the TRM, it doesn't require that we should
clear the usb3tousb2 bit before pipe ready. So let's enable the usb3
host after pipe ready to avoid the Type-C PHY initialization failure.

BUG=b:62644399, chromium:783464
TEST=run suspend_stess_test on Scarlet, usb device can work after resume

Change-Id: Ie597cbe35568c390460aa2fdbad0e66c6104c8d2
Reviewed-on: https://chromium-review.googlesource.com/896908
Commit-Ready: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: William Wu <william.wu@rock-chips.com>

Author: wuliangfeng

drivers/phy/rockchip/phy-rockchip-typec.c

@@ -877,6 +877,9 @@ static int _rockchip_usb3_phy_power_on(struct rockchip_typec_phy *tcphy)
 		regmap_read(tcphy->grf_regs, reg->offset, &val);
 		if (!(val & BIT(reg->enable_bit))) {
 			tcphy->mode |= new_mode & (MODE_DFP_USB | MODE_UFP_USB);
+
+			/* enable usb3 host */
+			tcphy_cfg_usb3_to_usb2_only(tcphy, false);
 			goto unlock_ret;
 		}
 		usleep_range(10, 20);