powertop: needs autoreconf

Commit 01048deab60 (package/powertop: bump to version 2.9) removed
autoreconf even though the remaining patch touches Makefile.am. Fix
this.

Fixes:
http://autobuild.buildroot.net/results/3bf/3bf8daee559e2978f8602c56397afda771299032/
http://autobuild.buildroot.net/results/f9b/f9b4f113a333107a972fa51bd0347eeb0d52496f/
http://autobuild.buildroot.net/results/067/0675826888b6f89e76291c7835839344300ca9f5/

Cc: Romain Naour <romain.naour@gmail.com>
Cc: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/powertop/powertop.mk

@@ -12,6 +12,8 @@ POWERTOP_DEPENDENCIES = pciutils ncurses libnl host-pkgconf \
 POWERTOP_LICENSE = GPL-2.0
 POWERTOP_LICENSE_FILES = COPYING
 POWERTOP_CONF_ENV = LIBS=$(TARGET_NLS_LIBS)
+# 0001-dont-force-stack-smashing-protection.patch
+POWERTOP_AUTORECONF = YES
 
 # Help powertop at finding the right ncurses library depending on
 # which one is available.