perf: make PKGV match kernel version

Have perf grab and use the kernel version it's built from for PKGV,
rather than the default perf recipe version, so the final packages get
the kernel version instead of the default 1.0, which represents a
backwards value from the previous recipe.

(From OE-Core rev: deb99cefe8be7fa63972edadf69f92d361b9a7c5)

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-kernel/perf/perf.bb

@@ -32,7 +32,7 @@ RDEPENDS_${PN} += "elfutils bash ${SCRIPTING_RDEPENDS}"
 
 PROVIDES = "virtual/perf"
 
-inherit kernel-arch pythonnative
+inherit linux-kernel-base kernel-arch pythonnative
 
 # needed for building the tools/perf Python bindings
 inherit python-dir
@@ -104,6 +104,10 @@ do_configure_prepend () {
     sed -i 's,-Werror ,,' ${S}/tools/perf/Makefile
 }
 
+python do_package_prepend() {
+    bb.data.setVar('PKGV', '${@get_kernelversion('${S}').split("-")[0]}', d)
+}
+
 PACKAGE_ARCH = "${MACHINE_ARCH}"
 
 FILES_${PN} += "${libexecdir}/perf-core"