tzdata: add missing comment for toolchain option dependencies

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tzdata/Config.in

@@ -1,3 +1,6 @@
+comment "tzdata needs an (e)glibc toolchain"
+	depends on !BR2_TOOLCHAIN_USES_GLIBC
+
 config BR2_PACKAGE_TZDATA
 	bool "tzdata"
 	depends on BR2_TOOLCHAIN_USES_GLIBC