ramips: revert fix rt3883 pci pinmux

This reverts commit dcdc6d9dad.

Even if described this way in the datasheet, it causes a bootloop on a
RT-N56U (v1):

  of-flash 1c000000.nor-flash: do_map_probe() failed for type cfi_probe
  of-flash 1c000000.nor-flash: do_map_probe() failed
  VFS: Cannot open root device “(null)” or unknown-block(0,0): error -6

Fixes: FS#1930

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/ramips/dts/rt3883.dtsi

@@ -310,7 +310,7 @@
 		pci_pins: pci {
 			pci {
 				ralink,group = "pci";
-				ralink,function = "pci-host1";
+				ralink,function = "pci-fnc";
 			};
 		};
 	};