ARM: u300: convert to sparse IRQs

This converts the U300 to use sparse IRQs, which is simple now
that the number of machines are reduced.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e91c7cd..0fb682d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -937,6 +937,7 @@
 	select COMMON_CLK
 	select GENERIC_GPIO
 	select ARCH_REQUIRE_GPIOLIB
+	select SPARSE_IRQ
 	help
 	  Support for ST-Ericsson U300 series mobile platforms.