hwmonio: split IoAccess object out

Split out the hwmon io access object from the sysfs namespace
into its own.

Change-Id: I8d1a45630117d1d503d0d5fa6061163911b695e8
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/Makefile.am b/Makefile.am
index d2b7989..0c26a6f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -25,6 +25,7 @@
 	fan_speed.cpp \
 	fan_pwm.cpp \
 	timer.cpp \
-	hwmon.cpp
+	hwmon.cpp \
+	hwmonio.cpp
 
 SUBDIRS = . msl test tools