utils: spkmodem: Add Makefile and gitignore

Change-Id: Ie3a6a777f5b667e881a4462bdd44a34dbace5520
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@no-log.org>
Reviewed-on: https://review.coreboot.org/23862
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/util/spkmodem_recv/Makefile b/util/spkmodem_recv/Makefile
new file mode 100644
index 0000000..5fdb195
--- /dev/null
+++ b/util/spkmodem_recv/Makefile
@@ -0,0 +1,7 @@
+PREFIX  ?= /usr/local
+INSTALL ?= install
+
+spkmodem-recv:
+	$(CC) -o $@ $@.c
+install: spkmodem-recv
+	$(INSTALL) $< -t $(PREFIX)/bin/