kernel: copy kernel 4.19 code to 5.4

No changes were done to the patches while coping them. Currently they do
not apply on top of kernel 5.4.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/generic/pending-5.4/302-mips_no_branch_likely.patch

@@ -0,0 +1,22 @@
+From: Felix Fietkau <nbd@nbd.name>
+Subject: mips: use -mno-branch-likely for kernel and userspace
+
+saves ~11k kernel size after lzma and ~12k squashfs size in the
+
+lede-commit: 41a039f46450ffae9483d6216422098669da2900
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+ arch/mips/Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/arch/mips/Makefile
++++ b/arch/mips/Makefile
+@@ -91,7 +91,7 @@ all-$(CONFIG_SYS_SUPPORTS_ZBOOT)+= vmlin
+ # machines may also.  Since BFD is incredibly buggy with respect to
+ # crossformat linking we rely on the elf2ecoff tool for format conversion.
+ #
+-cflags-y			+= -G 0 -mno-abicalls -fno-pic -pipe
++cflags-y			+= -G 0 -mno-abicalls -fno-pic -pipe -mno-branch-likely
+ cflags-y			+= -msoft-float
+ LDFLAGS_vmlinux			+= -G 0 -static -n -nostdlib
+ KBUILD_AFLAGS_MODULE		+= -mlong-calls