package/ethtool: switch to git snapshot

Upstream tarball does not include several header files leading to build
errors with older kernels. For details see:
https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/

Switch _SITE to git snapshot and add _AUTORECONF = YES which needs
host-pkgconf to fix subsequent configure error:

./configure: line 4723: PKG_PROG_PKG_CONFIG: command not found

./configure: line 5055: syntax error near unexpected token `MNL,'
./configure: line 5055: `    PKG_CHECK_MODULES(MNL, libmnl)'

Fixes:
http://autobuild.buildroot.net/results/69e/69e01b7f370920630d132fc43a40104fa5b3959f/

Signed-off-by: Bernd Kuhls <[email protected]>
Reviewed-by: Yegor Yefremov <[email protected]>
Signed-off-by: Thomas Petazzoni <[email protected]>

package/ethtool/ethtool.hash

@@ -1,5 +1,4 @@
-# From https://www.kernel.org/pub/software/network/ethtool/sha256sums.asc
-sha256  814171ea4b8026b081c0741dbbf32e6968311483ecf64711232faec2ac70a14c  ethtool-6.5.tar.xz
 # Locally calculated
+sha256  b1f5fa66f71c3bab9daeacbd77e010b52c47df0a711b216847f78405f3299189  ethtool-6.5.tar.gz
 sha256  8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643  COPYING
 sha256  5d632934396f90c82dfebe3c9512648bbb6333b406113d0cd331b0e0aa2d34a1  LICENSE

package/ethtool/ethtool.mk

@@ -5,8 +5,11 @@
 ################################################################################
 
 ETHTOOL_VERSION = 6.5
-ETHTOOL_SOURCE = ethtool-$(ETHTOOL_VERSION).tar.xz
-ETHTOOL_SITE = $(BR2_KERNEL_MIRROR)/software/network/ethtool
+ETHTOOL_SITE = https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/snapshot
+# needed only for autoreconf
+ETHTOOL_DEPENDENCIES = host-pkgconf
+# GIT version, shipped without configure
+ETHTOOL_AUTORECONF = YES
 ETHTOOL_LICENSE = GPL-2.0
 ETHTOOL_LICENSE_FILES = LICENSE COPYING
 ETHTOOL_CPE_ID_VENDOR = kernel