rpi-kernel: update to 5.4.68.

ship `arch/${_arch}/tools` in the headers package, as it's required to
build modules later on.

srcpkgs/rpi-kernel/template

@@ -5,11 +5,11 @@
 #
 #   https://www.raspberrypi.org/forums/viewtopic.php?f=29&t=269769
 
-_githash="1cbfe9ec6b3c714d1c336792dbaf867bde71d485"
+_githash="e82816db535e0489ffd1c31cd9b7e4969fce4171"
 _gitshort="${_githash:0:7}"
 
 pkgname=rpi-kernel
-version=5.4.65
+version=5.4.68
 revision=1
 wrksrc="linux-${_githash}"
 maintainer="Peter Bui <pbui@github.bx612.space>"
@@ -17,7 +17,7 @@ homepage="http://www.kernel.org"
 license="GPL-2.0-only"
 short_desc="The Linux kernel for Raspberry Pi (${version%.*} series [git ${_gitshort}])"
 distfiles="https://github.com/raspberrypi/linux/archive/${_githash}.tar.gz"
-checksum=43f8d6c7f98af6e72878347efa7fdcd3d4320526cbf198b608828b960a383028
+checksum=e0dc98befadb4c8c66aa0e73d9d79f10b20e29fb758ab870a0c6c708e3a0abb7
 python_version=2
 
 _kernver="${version}_${revision}"
@@ -95,7 +95,7 @@ do_configure() {
 
 	# LXD 4.2+ support
 	echo "CONFIG_BRIDGE_VLAN_FILTERING=y" >> "$defconfig"
-	
+
 	make ${makejobs} ${_cross} ARCH=${_arch} ${target}
 
 	# Always use our revision to CONFIG_LOCALVERSION to match our pkg version.
@@ -199,6 +199,9 @@ do_install() {
 	cp -a security/selinux/include ${hdrdest}/security/selinux
 	mkdir -p ${hdrdest}/tools/include
 	cp -a tools/include/tools ${hdrdest}/tools/include
+	if [ -d "arch/${_arch}/tools" ]; then
+		cp -a arch/${_arch}/tools ${hdrdest}/arch/${_arch}
+	fi
 
 	# copy arch includes for external modules
 	mkdir -p ${hdrdest}/arch/${_arch}