MdeModulePkg/EmmcDxe: Make sure no extra data is erased by EraseBlocks
    
    V3 changes:
    Add debug messages for new return path when successfully erase the
    specified blocks. Refine logic for calculating the size for writing
    zeros to device.
    
    V2 changes:
    
    The Trim command is not supported on all eMMC devices. For those devices
    that do not support such command, add codes to handle the scenario.
    
    Commit message:
    
    The current implementation of the Erase Block Protocol service
    EraseBlocks() uses the erase command. According to spec eMMC Electrical
    Standard 5.1, Section 6.6.9:
    
    The erasable unit of the eMMC is the "Erase Group"; Erase group is
    measured in write blocks that are the basic writable units of the Device.
    ...
    When the Erase is executed it will apply to all write blocks within an
    erase group.
    
    However, code logic in function EmmcEraseBlocks() does not check whether
    the blocks to be erased form complete erase groups. Missing such checks
    will lead to erasing extra data on the device.
    
    This commit will:
    a. If the device support the Trim command, use the Trim command to
    perform the erase operations for eMMC devices.
    
    According to the spec:
    Unlike the Erase command, the Trim function applies the erase operation to
    write blocks instead of erase groups.
    
    b. If the device does not support the Trim command, use the Erase command
    to erase the data in the erase groups. And write zeros to those blocks
    that cannot form a complete erase group.
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Hao Wu <hao.a.wu@intel.com>
    Reviewed-by: Star Zeng <star.zeng@intel.com>