phy: qcom-qusb2: add QUSB2 support for IPQ6018

Add the phy init sequence for the Super Speed ports found
on IPQ6018.

Signed-off-by: Kathiravan T <kathirav@codeaurora.org>
[baruch: add ipq6018_regs_layout[], drop binding change]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/b8c22dddf1f70d89e135fe1ae705ddc68e295ebb.1611756920.git.baruch@tkos.co.il


Signed-off-by: Vinod Koul <vkoul@kernel.org>