Vlv2TbltDevicePkg/PlatformFlashAccessLib: Add progress API

Vlv2TbltDevicePkg/PlatformFlashAccessLib: Add progress API

https://bugzilla.tianocore.org/show_bug.cgi?id=801

Add PerformFlashWriteWithProgress() to the PlatformFlashAccessLib.
This allows the platform to inform the user of progress when a
firmware storage device is being updated with a new firmware
image.

Cc: David Wei <david.wei@intel.com>
Cc: Mang Guo <mang.guo@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Reviewed-by: David Wei <david.wei@intel.com>