MAINTAINERS: add freescale USB PHY driver entry

Add freescale USB PHY driver entry

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20200703063924.29799-1-peter.chen@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>