brcmfmac: Delete second brcm folder hierarchy

BRCMF_FW_DEFAULT_PATH already defines the brcm folder, delete the second
folder to match with Linux firmware repository layout.

Fixes: 75729e11 ("brcmfmac: expose firmware config files through modinfo")
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210602144305.4481-1-matthias.bgg@kernel.org