This diff is already merged into the tree. Also you need to prepare and store brcmfmac43241b{0,4,5}-sdio.txt in /etc/firmware directory.

obsd-bwfm-4324.diff

Index: sys/dev/sdmmc/if_bwfm_sdio.c
===================================================================
RCS file: /cvs/src/sys/dev/sdmmc/if_bwfm_sdio.c,v
retrieving revision 1.39
diff -u -r1.39 if_bwfm_sdio.c
--- sys/dev/sdmmc/if_bwfm_sdio.c	26 Feb 2021 00:07:41 -0000	1.39
+++ sys/dev/sdmmc/if_bwfm_sdio.c	8 May 2021 00:13:29 -0000
@@ -360,6 +360,14 @@
 
 	switch (bwfm->sc_chip.ch_chip)
 	{
+	case BRCM_CC_43241_CHIP_ID:
+		if (bwfm->sc_chip.ch_chiprev <= 4)
+			chip = "43241b0";
+		else if (bwfm->sc_chip.ch_chiprev == 5)
+			chip = "43241b4";
+		else	/* bwfm->sc_chip.ch_chiprev >= 6 */
+			chip = "43241b5";
+		break;
 	case BRCM_CC_4330_CHIP_ID:
 		chip = "4330";
 		break;