Revert "ramips: add support for kernel 5.10"

This reverts commit b4aad29a1d.

This was accidentally folded into a single commit. Remove it and
apply it properly again.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ramips/patches-5.10/850-awake-rt305x-dwc2-controller.patch

@@ -1,15 +0,0 @@
---- a/drivers/usb/dwc2/platform.c
-+++ b/drivers/usb/dwc2/platform.c
-@@ -477,6 +477,12 @@ static int dwc2_driver_probe(struct plat
- 	if (retval)
- 		return retval;
- 
-+	/* Enable USB port before any regs access */
-+	if (readl(hsotg->regs + PCGCTL) & 0x0f) {
-+		writel(0x00, hsotg->regs + PCGCTL);
-+		/* TODO: mdelay(25) here? vendor driver don't use it */
-+	}
-+
- 	hsotg->needs_byte_swap = dwc2_check_core_endianness(hsotg);
- 
- 	retval = dwc2_get_dr_mode(hsotg);