Change p9_mss_freq_system to write attributes, errors for Cronus

  Honor the maximum support frequencies based on rank configs
  Remove the MEMVPD_FREQ attribute
  Fixup VPD tooling and accessors for new freq attrs
  Fix test case handling of master ranks
  Fix handling of empty MCS in Cronus

Change-Id: Ibbd42b130eb2d13bb9025a30c37bcd85445e7218
Original-Change-Id: I669ad0e81454f12368b484e826461ee76f7b9079
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/29878
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: PPE CI <ppe-ci+hostboot@us.ibm.com>
Reviewed-by: ANDRE A. MARIN <aamarin@us.ibm.com>
Reviewed-by: Matt K. Light <mklight@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/69784
Reviewed-by: Sachin Gupta <sgupta2m@in.ibm.com>
Tested-by: Sachin Gupta <sgupta2m@in.ibm.com>

src/import/chips/p9/procedures/xml/attribute_info/memory_mcs_attributes.xml

@@ -2118,22 +2118,6 @@
         <mssAccessorName>eff_vpd_version</mssAccessorName>
     </attribute>
 
-    <attribute>
-        <id>ATTR_MSS_NEST_CAPABLE_FREQUENCIES</id>
-        <targetType>TARGET_TYPE_MCBIST</targetType>
-        <description>
-            The NEST frequencies the memory chip can run at computed by the mss_freq.
-            The possibilities are ORed together.  The platform uses these value and
-            the MRW to determine what frequency to boot the fabric (nest) if it can.
-            There are two values: 8G and 9.6G
-        </description>
-        <initToZero></initToZero>
-        <valueType>uint64</valueType>
-        <enum>8_0G = 1, 9_6G = 2</enum>
-        <writeable/>
-        <mssAccessorName>nest_capable_frequencies</mssAccessorName>
-    </attribute>
-
     <attribute>
         <id>ATTR_MSS_VOLT_OVERRIDE</id>
         <targetType>TARGET_TYPE_MCBIST</targetType>