Enable FPGA advertisement pin for USB switch control.

[mndza]

This PR enables the FPGA advertisement pin (FPGA_ADV), which controls the USB switch in the CONTROL port.

FPGA designs or gateware requesting the "control_phy" resource are modified during build time to automatically include the advertisement submodule and relevant request handlers.

After a successful boot without pressing the PROGRAM button, the Apollo firmware transfers control of the USB switch to the FPGA. The gateware begins advertising port usage through the FPGA_ADV pin (FPGA_INT). If these messages cease, Apollo will reclaim control of the port. The port won't be handed back to the FPGA until a specific vendor request arrives.

The separate, relevant PRs for the dependencies are:

• gateware.usb.usb2.request: add claim to RequestHandlerInterface luna#225
• gateware.usb2: add port-specific hook support in USBDevice luna#226
• Add support for one-way FPGA advertisement pin apollo#22
• gateware.platform: add ApolloAdvertiser hook in boards with USB switch cynthion#23