This is to align the implementation with upstream `linux-firmware`.
Instead of moving these firmware files to `brcm` subdirectory and changing
their names, leave them in `cypress` subdirectory, keep their names intact
and use symbolic links to provide compatibility with Broadcom FullMAC
driver.
This gives more context to where the firmware comes from.
Signed-off-by: Kuan-Yi Li <kyli@abysm.org>