config.mak.uname: add FREAD_READS_DIRECTORIES for NonStop platform

The NonStop platform needs this configuration item specified as
UnfortunatelyYes so that config directory files are correctly processed.
Signed-off-by: NRandall S. Becker <rsbecker@nexbridge.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

config.mak.uname

@@ -490,6 +490,7 @@ ifeq ($(uname_S),NONSTOP_KERNEL)
 	OLD_ICONV = UnfortunatelyYes
 	NO_REGEX = NeedsStartEnd
 	NO_PTHREADS = UnfortunatelyYes
+	FREAD_READS_DIRECTORIES = UnfortunatelyYes
 
 	# Not detected (nor checked for) by './configure'.
 	# We don't have SA_RESTART on NonStop, unfortunalety.