usb: phy: Workaround for USB erratum-A005728

usb: phy: Workaround for USB erratum-A005728

PHY_CLK_VALID bit for UTMI PHY in USBDR does not set even
if PHY is providing valid clock. Workaround for this
involves resetting of PHY and check PHY_CLK_VALID bit
multiple times. If PHY_CLK_VALID bit is still not set even
after 5 retries, it would be safe to deaclare that PHY
clock is not available.
This erratum is applicable for USBDR less then ver 2.4.

Signed-off-by: Suresh Gupta <B42813@freescale.com>
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
Link: https://lore.kernel.org/r/20190624072219.15258-2-yinbo.zhu@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>