Add support for linking statically with CONFIG_STATIC=yes

This is loosly based on the following changes of chromiumos:

 - flashrom: Add default pkg-config definition.
   Change-Id: I28744af0fd2d2d0bcc4569a5fbef370321691267
 - Fix FT2232 feature on static builds.
   Change-Id: I70d4a7bda573b64cb18429a21792455b018c4cba

Corresponding to flashrom svn r1912.

Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
diff --git a/Makefile b/Makefile
index e100b16..de8464d 100644
--- a/Makefile
+++ b/Makefile
@@ -72,6 +72,11 @@
 PKG_CONFIG_LIBDIR ?= $(LIBS_BASE)/lib/pkgconfig
 endif
 
+ifeq ($(CONFIG_STATIC),yes)
+PKG_CONFIG += --static
+LDFLAGS += -static
+endif
+
 dummy_for_make_3_80:=$(shell printf "Build started on %s\n\n" "$$(date)" >$(BUILD_DETAILS_FILE))
 debug_shell = $(shell export LC_ALL=C ; { echo 'exec: export LC_ALL=C ; { $(1) ; }' >&2;  { $(1) ; } | tee -a $(BUILD_DETAILS_FILE) ; echo >&2 ; } 2>>$(BUILD_DETAILS_FILE))
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