wifi: brcm80211: remove unused structs

'brcmf_pcie_core_info' was added in
commit 9e37f045 ("brcmfmac: Adding PCIe bus layer support.")
but never used.

'brcms_c_bit_desc' last use was removed in
commit cdf4352f ("brcmsmac: Improve tx trace and debug support").

Remove them.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://msgid.link/20240526234553.286773-1-linux@treblig.org