MAINTAINERS: use correct filename for sdhci-bcm-kona

Use dashes not underscores.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Christian Daudt <csd@broadcom.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS

@@ -1983,7 +1983,7 @@ F:	arch/arm/boot/dts/bcm113*
 F:	arch/arm/boot/dts/bcm216*
 F:	arch/arm/boot/dts/bcm281*
 F:	arch/arm/configs/bcm_defconfig
-F:	drivers/mmc/host/sdhci_bcm_kona.c
+F:	drivers/mmc/host/sdhci-bcm-kona.c
 F:	drivers/clocksource/bcm_kona_timer.c
 
 BROADCOM BCM2835 ARM ARCHICTURE