Add missing cmis package (sonic-net#233)

Signed-off-by: Prince George <prgeor@microsoft.com>

Author: prgeor

setup.py

@@ -22,6 +22,7 @@
         'sonic_platform_base.sonic_thermal_control',
         'sonic_platform_base.sonic_xcvr',
         'sonic_platform_base.sonic_xcvr.fields',
+        'sonic_platform_base.sonic_xcvr.fields.public',
         'sonic_platform_base.sonic_xcvr.mem_maps',
         'sonic_platform_base.sonic_xcvr.mem_maps.public',
         'sonic_platform_base.sonic_xcvr.api',