MIPS: sibyte: Amend dependencies for SIBYTE_BUS_WATCHER

SIBYTE_BUS_WATCHER is only visible if CONFIG_SIBYTE_BCM112X
or CONFIG_SIBYTE_SB1250 is selected according to the
arch/mips/sibyte/Makefile.
This fixes the following build problem:

arch/mips/mm/cerr-sb1.c:254: undefined reference to `check_bus_watcher'

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Acked-by: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: sibyte-users@bitmover.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5482/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/sibyte/Kconfig

@@ -147,7 +147,8 @@ config SIBYTE_CFE_CONSOLE
 
 config SIBYTE_BUS_WATCHER
 	bool "Support for Bus Watcher statistics"
-	depends on SIBYTE_SB1xxx_SOC
+	depends on SIBYTE_SB1xxx_SOC && \
+		(SIBYTE_BCM112X || SIBYTE_SB1250)
 	help
 	  Handle and keep statistics on the bus error interrupts (COR_ECC,
 	  BAD_ECC, IO_BUS).