OVMF: drop i686 support (#475022)

  sourceDebug ? false,

  projectDscPath ?

    {

      i686 = "OvmfPkg/OvmfPkgIa32.dsc";

      x86_64 = "OvmfPkg/OvmfPkgX64.dsc";

      aarch64 = "ArmVirtPkg/ArmVirtQemu.dsc";

      riscv64 = "OvmfPkg/RiscVVirt/RiscVVirtQemu.dsc";

      or (throw "Unsupported OVMF `projectDscPath` on ${stdenv.hostPlatform.parsed.cpu.name}"),

  fwPrefix ?

    {

      i686 = "OVMF";

      x86_64 = "OVMF";

      aarch64 = "AAVMF";

      riscv64 = "RISCV_VIRT";

    }

    .${stdenv.hostPlatform.parsed.cpu.name}

      or (throw "Unsupported OVMF `fwPrefix` on ${stdenv.hostPlatform.parsed.cpu.name}"),

  metaPlatforms ? edk2.meta.platforms,

  metaPlatforms ? lib.subtractLists lib.platforms.i686 edk2.meta.platforms,

}:

let

  platformSpecific = {

    i686.msVarsArgs = {

      flavor = "OVMF";

      archDir = "Ia32";

    };

    x86_64.msVarsArgs = {

      flavor = "OVMF_4M";

      archDir = "X64";