Move ODROID patches (#1415)

The patches for ODROID-C2/C4 don't apply to Linux 5.12 used in
ODROID-N2. Move ODROID-C2/C4 patches to kernel version specific
directory so they don't get applied for ODROID-N2.

(cherry picked from commit 64d3cd88a1)

buildroot-external/board/hardkernel/patches/linux/board-odroidc2-add-uartA-uartC.patch

@@ -1,32 +0,0 @@
-diff --git a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts
-index 1cc9dc6..9f48dff 100644
---- a/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts
-+++ b/arch/arm64/boot/dts/amlogic/meson-gxbb-odroidc2.dts
-@@ -16,6 +16,8 @@
- 
- 	aliases {
- 		serial0 = &uart_AO;
-+		serial1 = &uart_A;
-+		serial2 = &uart_C;
- 		ethernet0 = &ethmac;
- 	};
- 
-@@ -290,6 +355,18 @@
- 	pinctrl-names = "default";
- };
- 
-+&uart_A {
-+	status = "disabled";
-+	pinctrl-0 = <&uart_a_pins>;
-+	pinctrl-names = "default";
-+};
-+
-+&uart_C {
-+	status = "disabled";
-+	pinctrl-0 = <&uart_c_pins>;
-+	pinctrl-names = "default";
-+};
-+
- &usb0_phy {
- 	status = "okay";
- 	phy-supply = <&usb_otg_pwr>;