Refactor the routines for "calculating" the size of the WARP microcode. The

Refactor the routines for "calculating" the size of the WARP microcode. The
    two routines (one for G200 and one for G400) were replaced with static
    const variables and a single function that returns the correct size.
    The code to generate an error if the allocated WARP region is too small
    was refactored from mga_warp_install_{g200,g400}_microcode to
    mga_wrap_install_microcode.
mga_warp_microcode_size is global to the MGA DRM because it will soon be
    used by code in another file.