SignedCapsulePkg/SystemFirmwareUpdateDxe: Use progress API

SignedCapsulePkg/SystemFirmwareUpdateDxe: Use progress API

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

Use PlatformFlashWriteWithProgress() instead of PlatformFLashWrite()
so the user can be informed of the progress as a capsule is used
to update a firmware image in a firmware device.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Star Zeng <star.zeng@intel.com>