phy: starfive: jh7110-usb: Fix link configuration to controller

In order to connect the USB 2.0 PHY to its controller, we also need to
set "u0_pdrstn_split_sw_usbpipe_plugen" [1]. Some downstream U-Boot
versions did that, but upstream firmware does not, and the kernel must
not rely on such behavior anyway. Failing to set this left the USB
gadget port invisible to connected hosts behind.

Link: https://doc-en.rvspace.org/JH7110/TRM/JH7110_TRM/sys_syscon.html#sys_syscon__section_b3l_fqs_wsb

 [1]
Fixes: 16d3a71c ("phy: starfive: Add JH7110 USB 2.0 PHY driver")
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20241015070444.20972-2-minda.chen@starfivetech.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>