usb: ehci-mx6: Add i.MX93 support

i.MX93 uses the same USB IP as i.MX8MM. It can then reuse the ehci-mx6
driver.

Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Reviewed-by: Fabio Estevam <festevam@gmail.com>