package/ethtool: bump version to 6.6

Switch back to upstream-provided tarball after upstream fixed the
inclusion of header files needed for older kernels:
https://git.kernel.org/pub/scm/network/ethtool/ethtool.git/commit/?id=988279e051e7a51d0b9e54a7366602ba2879d114

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ethtool/ethtool.hash

@@ -1,4 +1,5 @@
+# From https://www.kernel.org/pub/software/network/ethtool/sha256sums.asc
+sha256  833a8493cb9cd5809ab59743092d9a38742c282290800e9626407511bbcebf9e  ethtool-6.6.tar.xz
 # Locally calculated
-sha256  b1f5fa66f71c3bab9daeacbd77e010b52c47df0a711b216847f78405f3299189  ethtool-6.5.tar.gz
 sha256  8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643  COPYING
 sha256  5d632934396f90c82dfebe3c9512648bbb6333b406113d0cd331b0e0aa2d34a1  LICENSE

package/ethtool/ethtool.mk

@@ -4,12 +4,9 @@
 #
 ################################################################################
 
-ETHTOOL_VERSION = 6.5
-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_VERSION = 6.6
+ETHTOOL_SOURCE = ethtool-$(ETHTOOL_VERSION).tar.xz
+ETHTOOL_SITE = $(BR2_KERNEL_MIRROR)/software/network/ethtool
 ETHTOOL_LICENSE = GPL-2.0
 ETHTOOL_LICENSE_FILES = LICENSE COPYING
 ETHTOOL_CPE_ID_VENDOR = kernel