arm64: dts: renesas: r8a774a1: Fix USB 2.0 clocks

Similarly to what done for the r8a7796 with commit 737e05bf
("arm64: dts: renesas: revise properties for R-Car Gen3 SoCs'
usb 2.0"), this patch lists the clock for the USB High-Speed Module
(HS-USB) with the USB2.0 Host (EHCI/OHCI) IP DT node, and it lists
the clock for the USB2.0 Host IP with the HS-USB module DT node.

Fixes: 4c2c2fb9 ("arm64: dts: renesas: r8a774a1: Add USB2.0 phy and host(EHCI/OHCI) device nodes")
Fixes: ed898d4f ("arm64: dts: renesas: r8a774a1: Add USB-DMAC and HSUSB device nodes")
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>