brcmfmac: Demote non-compliant kernel-doc headers

Fixes the following W=1 kernel build warning(s):

 drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c:2040: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c:1295: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

Cc: Franky Lin <franky.lin@broadcom.com>
Cc: Hante Meuleman <hante.meuleman@broadcom.com>
Signed-off-by: Yang Shen <shenyang39@huawei.com>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210517050141.61488-5-shenyang39@huawei.com

drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c

@@ -2037,7 +2037,7 @@ static void brcmf_p2p_get_current_chanspec(struct brcmf_p2p_info *p2p,
 }
 
 /**
- * Change a P2P Role.
+ * brcmf_p2p_ifchange - Change a P2P Role.
  * @cfg: driver private data for cfg80211 interface.
  * @if_type: interface type.
  * Returns 0 if success.

drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c

@@ -1291,7 +1291,7 @@ static void brcmf_sdio_free_glom(struct brcmf_sdio *bus)
 	}
 }
 
-/**
+/*
  * brcmfmac sdio bus specific header
  * This is the lowest layer header wrapped on the packets transmitted between
  * host and WiFi dongle which contains information needed for SDIO core and