cpupower: keep header files for other packages and package systemd service

When having a DEPENDS against cpupower it need to leave its header files.
Remove that cleanup that has been present since the beginning of the recipe
without any (to me) known reason.

cpupower ship a systemd service and config file in kernel source tree
since kernel 6.16. Package them as a separate package cpupower-systemd to
be installed if wanted.

Add cpupower to packagegroup-meta-oe to be included in builds of all
packages.

Signed-off-by: Peter Bergin <peter@berginkonsult.se>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-core/packagegroups/packagegroup-meta-oe.bb

@@ -52,6 +52,7 @@ RDEPENDS:packagegroup-meta-oe = "\
 
 RDEPENDS:packagegroup-meta-oe-benchmarks = "\
     bonnie++ \
+    cpupower \
     dbench \
     dhrystone \
     fio \

meta-oe/recipes-kernel/cpupower/cpupower.bb

@@ -5,6 +5,8 @@ LICENSE = "GPL-2.0-only"
 DEPENDS = "pciutils gettext-native"
 PROVIDES = "virtual/cpupower"
 
+B = "${WORKDIR}/${BPN}-${PV}"
+
 inherit kernelsrc kernel-arch bash-completion
 
 do_populate_lic[depends] += "virtual/kernel:do_shared_workdir"
@@ -19,17 +21,16 @@ do_compile() {
 
 do_install() {
     oe_runmake DESTDIR=${D} install
-    # Do not ship headers
-    rm -rf ${D}${includedir}
     chown -R root:root ${D}
 }
 
 PACKAGE_ARCH = "${MACHINE_ARCH}"
+PACKAGES =+ "${PN}-systemd"
+
+FILES:${PN}-systemd = "${sysconfdir}/cpupower-service.conf ${systemd_unitdir}"
 
 RDEPENDS:${PN} = "bash"
 
 python do_package:prepend() {
     d.setVar('PKGV', d.getVar("KERNEL_VERSION").split("-")[0])
 }
-
-B = "${WORKDIR}/${BPN}-${PV}"