This patch adds the ST glue logic to manage the DWC3 HC
on STiH407 SoC family. It manages the powerdown signal,
and configures the internal glue logic and syscfg registers.

[ balbi@ti.com : actually switch over to of_platform_depopulate() ]
Signed-off-by: NGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: NPeter Griffin <peter.griffin@linaro.org>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NFelipe Balbi <balbi@ti.com>