irqchip: bcm7120-l2: Decouple driver from brcmstb-l2

Some chips, such as BCM6328, only require bcm7120-l2.  Some BCM7xxx STB
configurations only require brcmstb-l2.  Treat them as two separate
entities, and update the mach-bcm dependencies to reflect the change.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lkml.kernel.org/r/1415342669-30640-13-git-send-email-cernekee@gmail.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 038b59e..9efe5f1 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -48,6 +48,11 @@
 	select MULTI_IRQ_HANDLER
 	select SPARSE_IRQ
 
+config BCM7120_L2_IRQ
+	bool
+	select GENERIC_IRQ_CHIP
+	select IRQ_DOMAIN
+
 config BRCMSTB_L2_IRQ
 	bool
 	select GENERIC_IRQ_CHIP