ARM: dts: s5pv210: align EHCI/OHCI nodes with dtschema

The node names should be generic and USB DT schema expects "usb" names.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220314181948.246434-2-krzysztof.kozlowski@canonical.com