brcm: revert firmware files for Cypress devices

Recent commit added firmware files into the brcm subdirectory. However,
it restored some firmware files that were replaced by firmware files
provided by Cypress using symbolic links. Hence removing these files
once more.

Reported-by: John Keeping <john@metanate.com>
Fixes: 0707b2f2

 ("brcm: add/update firmware files for brcmfmac driver")
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>