ethtool: drop dependency on kernel 6.6

Since now we default to 6.12 and we dropped any support for kernel 6.6,
drop any dependency on it.

Signed-off-by: Christian Marangi <[email protected]>

package/network/utils/ethtool/Makefile

@@ -58,9 +58,7 @@ CONFIGURE_ARGS += --disable-netlink --disable-pretty-dump
 endif
 
 # enable support for input_xfrm with kernels newer than 6.6
-ifeq ($(CONFIG_LINUX_6_6),)
 CONFIGURE_ARGS += --enable-rss-input-xfrm
-endif
 
 define Package/ethtool/install
 	$(INSTALL_DIR) $(1)/usr/sbin