phy: qcom-snps: Add SNPS USB PHY driver for QCOM based SOCs

This adds the SNPS FemtoPHY V2 driver used in QCOM SOCs.  There
are potentially multiple instances of this UTMI PHY on the
SOC, all which can utilize this driver.  The V2 driver will
have a different register map compared to V1.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reviewed-by: Philipp Zabel <pza@pengutronix.de>
Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/1588636467-23409-3-git-send-email-wcheng@codeaurora.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>