pseq: Add BMC dump method to Services class

Add a method to the Services class to create a BMC dump.

Tested:
* Delete all BMC dumps on system
* Verify no BMC dumps exist
* Call method to create a BMC dump
* Verify dump is created
* Expand dump
* Verify dump has expected contents
* Call method to create a BMC dump again
* Verify a second dump is created

Change-Id: Ia4b9753e9ba15ed61bf5446006713875e738b3dd
Signed-off-by: Shawn McCarney <shawnmm@us.ibm.com>
diff --git a/phosphor-power-sequencer/src/services.hpp b/phosphor-power-sequencer/src/services.hpp
index 255e2c5..3fa0f6f 100644
--- a/phosphor-power-sequencer/src/services.hpp
+++ b/phosphor-power-sequencer/src/services.hpp
@@ -128,6 +128,11 @@
                     size_t instance = 0) = 0;
 
     /**
+     * Creates a BMC dump.
+     */
+    virtual void createBMCDump() = 0;
+
+    /**
      * Clear any cached data.
      *
      * Some data may be cached for performance reasons, such as hardware
@@ -201,6 +206,9 @@
         return std::make_unique<PMBus>(path, driverName, instance);
     }
 
+    /** @copydoc Services::createBMCDump() */
+    virtual void createBMCDump() override;
+
     /** @copydoc Services::clearCache() */
     virtual void clearCache() override
     {