util/superiotool: Add initial support for Exar XR28V384.

Datasheet
https://www.exar.com/content/document.ashx?id=21368

Add support for Exar chip used on a custom board
that was designed to connect to the Olive Hill Plus
development platform. The register dump was verified
on the Olive Hill Plus platform.

Change-Id: Ibd3e13eefb706bd99b6e5b38634f6855b39848ab
Signed-off-by: Derek Waldner <derek.waldner.os@gmail.com>
Reviewed-on: https://review.coreboot.org/14367
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/util/superiotool/Makefile b/util/superiotool/Makefile
index 1cd098f..f6d9685 100644
--- a/util/superiotool/Makefile
+++ b/util/superiotool/Makefile
@@ -28,8 +28,8 @@
          -Werror-implicit-function-declaration -ansi -pedantic $(VERSION)
 LDFLAGS += -lz
 
-OBJS = superiotool.o serverengines.o ali.o fintek.o ite.o nsc.o nuvoton.o \
-       smsc.o winbond.o infineon.o
+OBJS = superiotool.o serverengines.o ali.o exar.o fintek.o ite.o nsc.o \
+       nuvoton.o smsc.o winbond.o infineon.o
 
 OS_ARCH = $(shell uname)
 ifeq ($(OS_ARCH), Darwin)