Fix mingw detection on Windows 7 (NT-6.1)

Hopefully also for other non-XP Windows build environments.

Change-Id: I7f856dc4847c4ca9197b1935b7a9b9071b46c70a
Signed-off-by: Miklós Márton <martonmiklosqdev@gmail.com>
Reviewed-on: https://review.coreboot.org/23865
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/Makefile b/Makefile
index 943d88d..746d8d6 100644
--- a/Makefile
+++ b/Makefile
@@ -93,10 +93,11 @@
 
 # HOST_OS is only used to work around local toolchain issues.
 HOST_OS ?= $(shell uname)
-ifeq ($(HOST_OS), MINGW32_NT-5.1)
+ifeq ($(findstring MINGW, $(HOST_OS)), MINGW)
 # Explicitly set CC = gcc on MinGW, otherwise: "cc: command not found".
 CC = gcc
 endif
+
 ifneq ($(HOST_OS), SunOS)
 STRIP_ARGS = -s
 endif
diff --git a/util/ich_descriptors_tool/Makefile b/util/ich_descriptors_tool/Makefile
index d1b5eae..c32e30b 100644
--- a/util/ich_descriptors_tool/Makefile
+++ b/util/ich_descriptors_tool/Makefile
@@ -22,6 +22,16 @@
 # completely ignored by gnumake.
 CFLAGS ?= -Os -Wall -Wshadow
 
+HOST_OS ?= $(shell uname)
+ifeq ($(findstring MINGW, $(HOST_OS)), MINGW)
+# Explicitly set CC = gcc on MinGW, otherwise: "cc: command not found".
+CC = gcc
+EXEC_SUFFIX := .exe
+# Some functions provided by Microsoft do not work as described in C99 specifications. This macro fixes that
+# for MinGW. See http://sourceforge.net/p/mingw-w64/wiki2/printf%20and%20scanf%20family/ */
+FLASHROM_CFLAGS += -D__USE_MINGW_ANSI_STDIO=1
+endif
+
 override TARGET_OS := $(shell $(CC) $(CPPFLAGS) -E $(SHAREDSRCDIR)/os.h | grep -v '^\#' | grep '"' | \
 			cut -f 2 -d'"')
 
@@ -31,13 +41,6 @@
 CFLAGS += -Wno-format
 endif
 
-ifeq ($(TARGET_OS), MinGW)
-EXEC_SUFFIX := .exe
-# Some functions provided by Microsoft do not work as described in C99 specifications. This macro fixes that
-# for MinGW. See http://sourceforge.net/p/mingw-w64/wiki2/printf%20and%20scanf%20family/ */
-FLASHROM_CFLAGS += -D__USE_MINGW_ANSI_STDIO=1
-endif
-
 ifeq ($(WARNERROR), yes)
 CFLAGS += -Werror
 endif