MFD: ucb1x00: convert to use genirq

Convert the ucb1x00 driver to use genirq's interrupt services, rather
than its own private implementation.  This allows a wider range of
drivers to use the GPIO interrupts (such as the gpio_keys driver)
without being aware of the UCB1x00's private IRQ system.

This prevents the UCB1x00 core driver from being built as a module,
so adjust the configuration to add that restriction.

Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index cd13e9f..28a301b 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -847,8 +847,9 @@
 
 # Chip drivers
 config MCP_UCB1200
-	tristate "Support for UCB1200 / UCB1300"
-	depends on MCP
+	bool "Support for UCB1200 / UCB1300"
+	depends on MCP_SA11X0
+	select MCP
 
 config MCP_UCB1200_TS
 	tristate "Touchscreen interface support"