MAINTAINERS: Add BCM63146 to bcmbca arch entry

Add BCM63146 related files to BCMBCA ARCH maintainer list entry

Signed-off-by: William Zhang <william.zhang@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

MAINTAINERS

@@ -3787,6 +3787,7 @@ F:	arch/arm64/boot/dts/broadcom/bcmbca/*
 N:	bcmbca
 N:	bcm[9]?47622
 N:	bcm[9]?4912
+N:	bcm[9]?63146
 N:	bcm[9]?63158
 N:	bcm[9]?63178
 N:	bcm[9]?6756