[dev][smdev] Fixed Makefile to create bin folder

[Ari Malinen]

Its hard to write ebuilds for smdev because this line is missing from smdev:
@mkdir -p ${DESTDIR}${PREFIX}/bin

Here is patch:
http://koti.kapsi.fi/~deferi/patches/smdev-git-create-bin.diff

diff --git a/Makefile b/Makefile
index 48749e5..59d844f 100644
--- a/Makefile
+++ b/Makefile
@@ -53,6 +53,7 @@ util.a: $(LIB)
 
 install: all
        @echo installing executable to $(DESTDIR)$(PREFIX)/bin
+       @mkdir -p ${DESTDIR}${PREFIX}/bin
        @cp -f $(BIN) $(DESTDIR)$(PREFIX)/bin
        @cd $(DESTDIR)$(PREFIX)/bin && chmod 755 $(BIN)