perf: fix build with latest kernel

Kernel 6.7-rc1 commit 02e85f74668e ("tools: arm64: Add a Makefile for
generating sysreg-defs.h") uses files from arch/arm64/tools/,
gen-sysreg.awk and sysreg.
Without the files the build of perf fails independent of the used
architecture (confirmed with armv7 and qemux86_64).

As arch/arm64/tools/ has been added with 5.13 allow perf to build
even it that directory does not exist.

Add arch/arm64/tools/ to PERF_SRC.

Fixes:
| make[3]: *** No rule to make target '.../qemux86_64-tdx-linux/perf/1.0/perf-1.0/arch/arm64/tools/gen-sysreg.awk', needed by '.../qemux86_64-tdx-linux/perf/1.0/perf-1.0/tools/arch/arm64/include/generated/asm/sysreg-defs.h'.  Stop.
| make[2]: *** [Makefile.perf:456: arm64-sysreg-defs] Error 2

(From OE-Core rev: 432b4ac20dadb9c08596266fce4f3941d4856c7e)

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-kernel/perf/perf.bb

@@ -138,6 +138,7 @@ PERF_SRC ?= "Makefile \
              tools/perf \
              tools/scripts \
              scripts/ \
+             arch/arm64/tools \
              arch/${ARCH}/Makefile \
 "
 
@@ -183,7 +184,8 @@ python copy_perf_source_from_kernel() {
         src = oe.path.join(src_dir, s)
         dest = oe.path.join(dest_dir, s)
         if not os.path.exists(src):
-            bb.fatal("Path does not exist: %s. Maybe PERF_SRC does not match the kernel version." % src)
+            bb.warn("Path does not exist: %s. Maybe PERF_SRC lists more files than what your kernel version provides and needs." % src)
+            continue
         if os.path.isdir(src):
             oe.path.copyhardlinktree(src, dest)
         else: