The Platform Flash XL is not supported for 7 Series configuration. File generation is not supported in PROMGen, (see (Xilinx Answer 42943)), and Indirect Programming is not supported in iMPACT.
Platform Flash XL is not fully voltage compatible with Virtex-7 FPGA, and there are more effective solutions available in terms of density and speed.
Third-party vendors offer higher density BPI NOR flash. For a high-speed solution, Synchronous BPI is more effective with 7 Series FPGAs.