build: build coreboot on mingw.

regex, pdcurses, wsock(for itohl) are seperated libraries. mmap and unmmap are
ported from git.

Issues:
1. The length of command line is limited. That makes the Thather can not be built
  because too many obj.o need to be built.

Change-Id: I1d60ec5c7720c1e712e246c4cd12e4b718fed05f
Signed-off-by: Zheng Bao <zheng.bao@amd.com>
Signed-off-by: Zheng Bao <fishbaozi@gmail.com>
Reviewed-on: http://review.coreboot.org/1604
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>

util/nvramtool/Makefile.inc

@@ -35,6 +35,11 @@ nvramtoolobj += cmos_lowlevel.o cmos_ops.o common.o compute_ip_checksum.o
 nvramtoolobj += hexdump.o input_file.o layout.o accessors/layout-common.o accessors/layout-text.o accessors/layout-bin.o lbtable.o
 nvramtoolobj += reg_expr.o cbfs.o accessors/cmos-mem.o
 
+ifeq ($(shell uname -s 2>/dev/null | cut -c-7), MINGW32)
+NVRAMTOOLLDFLAGS += -lregex -lwsock32
+nvramtoolobj += win32mmap.o
+endif
+
 $(objutil)/nvramtool $(objutil)/nvramtool/accessors $(objutil)/nvramtool/cli:
 	mkdir -p $@