Add a directory by kernel instead of a common root, add qnap-301w and rpi4 kernel 6.1 suppport

6.1/target/linux/generic/hack-6.1/321-powerpc_crtsavres_prereq.patch

@@ -0,0 +1,38 @@
+From 107c0964cb8db7ca28ac5199426414fdab3c274d Mon Sep 17 00:00:00 2001
+From: "Alexandros C. Couloumbis" <alex@ozo.com>
+Date: Fri, 7 Jul 2017 17:14:51 +0200
+Subject: hack: arch: powerpc: drop register save/restore library from modules
+
+Upstream GCC uses a libgcc function for saving/restoring registers. This
+makes the code bigger, and upstream kernels need to carry that function
+for every single kernel module. Our GCC is patched to avoid those
+references, so we can drop the extra bloat for modules.
+
+lede-commit: e8e1084654f50904e6bf77b70b2de3f137d7b3ec
+Signed-off-by: Alexandros C. Couloumbis <alex@ozo.com>
+---
+ arch/powerpc/Makefile | 1 -
+ 1 file changed, 1 deletion(-)
+
+--- a/arch/powerpc/Makefile
++++ b/arch/powerpc/Makefile
+@@ -42,19 +42,6 @@ machine-$(CONFIG_PPC64) += 64
+ machine-$(CONFIG_CPU_LITTLE_ENDIAN) += le
+ UTS_MACHINE := $(subst $(space),,$(machine-y))
+ 
+-# XXX This needs to be before we override LD below
+-ifdef CONFIG_PPC32
+-KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
+-else
+-ifeq ($(call ld-ifversion, -ge, 22500, y),y)
+-# Have the linker provide sfpr if possible.
+-# There is a corresponding test in arch/powerpc/lib/Makefile
+-KBUILD_LDFLAGS_MODULE += --save-restore-funcs
+-else
+-KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
+-endif
+-endif
+-
+ ifdef CONFIG_CPU_LITTLE_ENDIAN
+ KBUILD_CFLAGS	+= -mlittle-endian
+ KBUILD_LDFLAGS	+= -EL