Add sensor cache read as an explorer inband command

A read of the sensor cache is done via 2 32-byte MMIO reads. There is
no system implementation that can handle a 32 byte transaction size
currently, but implement the structure and wrapper so it is available.

Change-Id: Ib7e11d08fcc2989de0ee79ca3405a5c268b779c3
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/67106
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: ANDRE A. MARIN <aamarin@us.ibm.com>
Reviewed-by: Benjamin Gass <bgass@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/80968
Reviewed-by: RAJA DAS <rajadas2@in.ibm.com>
Tested-by: RAJA DAS <rajadas2@in.ibm.com>

src/import/chips/ocmb/explorer/procedures/hwp/memory/lib/shared/exp_consts.H

@@ -49,6 +49,7 @@ enum ffdc_codes
     EXP_I2C_GET_FIELD = 0x0000,
     EXP_I2C_SET_FIELD = 0x0001,
     READ_HOST_FW_RESPONSE_STRUCT = 0x0003,
+    READ_SENSOR_CACHE_STRUCT = 0x0004,
 };
 
 namespace i2c