MFC r352853, r352903-r352904, r352936-r352937

r352853:
arm64: rockchip: Add usb2phy driver

This driver is for the usb phy present on rockchip SoC.
It only support RK3399 and host mode for now.
The driver expose the usb clock needed by the usb controller.

r352903:
arm64: rockchip: correct reset value

If bit is 0 the reset is not asserted.
Also register our self as a reset provider, this was commented
in r352850

Reported by: mmel

r352904:
arm64: rockchip: rk_clk_pll: Check mode on recalc

If the pll is in slow or deep slow mode return the correct frequency.

r352936:
arm64: rockchip: rk805: Switch to iicdev_{readfrom,writeto}

This simpify the code a bit.

r352937:
syr827: Switch to iicdev_{readfrom,writeto}

Also use IIC_INTRWAIT as we need this to work with the rockchip i2c driver.