USB: EHCI: ehci-mv: add HSIC support

Some special dance is needed to initialize the HSIC port.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20191221065008.266445-2-lkundrak@v3.sk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>