package/util-linux: lsfd needs headers >= 3.19

lsfd depends on kcmp.h which is only exported since kernel 3.19 and
https://github.com/torvalds/linux/commit/3f4994cfc15f38a3159c6e3a4b3ab2e1481a6b02
resulting in the following build failure since bump to version 2.38 in
commit ee978e853a6a4c9bb5ed661c1ae704e79f155a35:

configure: error: lsfd selected, but required linux/kcmp.h header file not available

Fixes:
 - http://autobuild.buildroot.org/results/555c272fe0f966f7f46d493236cb6dabeca24d9b

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/util-linux/Config.in

@@ -206,10 +206,15 @@ config BR2_PACKAGE_UTIL_LINUX_LOSETUP
 config BR2_PACKAGE_UTIL_LINUX_LSFD
 	bool "lsfd"
 	depends on BR2_USE_MMU # libsmartcols
+	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_19
 	select BR2_PACKAGE_UTIL_LINUX_LIBSMARTCOLS
 	help
 	  List file descriptors (modern replacement for lsof)
 
+comment "lsfd needs a toolchain w/ headers >= 3.19"
+	depends on BR2_USE_MMU
+	depends on !BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_19
+
 config BR2_PACKAGE_UTIL_LINUX_LSLOGINS
 	bool "lslogins"
 	depends on BR2_USE_MMU # libsmartcols