[ARM] pxa: make mainstone use the generic PWM backlight driver

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-pxa/Kconfig b/arch/arm/mach-pxa/Kconfig
index b7a3281..2d71130 100644
--- a/arch/arm/mach-pxa/Kconfig
+++ b/arch/arm/mach-pxa/Kconfig
@@ -41,6 +41,7 @@
 config MACH_MAINSTONE
 	bool "Intel HCDDBBVA0 Development Platform"
 	select PXA27x
+	select HAVE_PWM
 
 config ARCH_PXA_IDP
 	bool "Accelent Xscale IDP"