Update to buildroot 2016.05

 - package/dropbear: Add BR2_PACKAGE_DROPBEAR_SERVER option
 - host-fakeroot: re-run autotools to fix build on ppc64le host
 - linux-firmware: Update bnx2x firmware version

Configuration changes:

 - BR2_BINUTILS_VERSION_2_26_X selects the most modern version
 - BR2_LINUX_KERNEL_CUSTOM_VERSION replaces LATEST_VERSION as upstream
   tracks a newer version than we are using
 - BR2_PACKAGE_SKIBOOT is default y if (BR2_OPENPOWER_PLATFORM && BR2_powerpc_power8)
   BR2_PACKAGE_POWERPC_UTILS is selected by petitboot
 - The BR2_TOOLCHAIN_BUILDROOT_LIBSTDCPP symbol was never upstreamed.
   It's implemented by BR2_INSTALL_LIBSTDCPP in upstream, and we don't
   have it enabled.

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower/configs/openpower_p9_mambo_defconfig b/openpower/configs/openpower_p9_mambo_defconfig
index a74d8fb..e0d8783 100644
--- a/openpower/configs/openpower_p9_mambo_defconfig
+++ b/openpower/configs/openpower_p9_mambo_defconfig
@@ -4,6 +4,7 @@
 BR2_KERNEL_HEADERS_4_4=y
 BR2_GLIBC_VERSION_2_23=y
 BR2_BINUTILS_EXTRA_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
+BR2_BINUTILS_VERSION_2_26_X=y
 BR2_EXTRA_GCC_CONFIG_OPTIONS="--enable-targets=powerpc64-linux"
 BR2_ENABLE_LOCALE_PURGE=y
 BR2_ENABLE_LOCALE_WHITELIST="C en_US"
@@ -29,6 +30,7 @@
 BR2_PACKAGE_MDADM=y
 BR2_PACKAGE_NCURSES_WCHAR=y
 BR2_PACKAGE_DROPBEAR=y
+# BR2_PACKAGE_DROPBEAR_SERVER is not set
 BR2_PACKAGE_ETHTOOL=y
 BR2_PACKAGE_NETCAT=y
 BR2_PACKAGE_RSYNC=y