This patch removes the former use of ram_fs, fs_rom, and fs_report from
the subsystem and uses a report_rom instead. The fs-based reporting was
introduced to accommodate automatically instantiated usb_block drivers,
which turned out to be impractical for the sculpt scenario.
Without this patch, usb_drv would issue a resource request when
assigning a USB device to a VM in the sculpt scenario.
Furthermore, the patch adjusts the intel_fb quota to enable it on
devices where the driver allocates the framebuffer in many 4K pieces.
This is a drivers subsystem that starts the most fundamental
(framebuffer, input, block) device drivers dynamically, depending on the
runtime-detected devices. The discovered block devices are reported
as a "block_devices" report.
