[ARM] pxa: allow PXA to be built for multiple platforms

Convert the 'choice' into a 'menu' to allow multiple platforms to be
selected.

This means to do a build check across PXA, you don't end up spending
a lifetime building _twenty_ sodding kernels.

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 5da7a68..2563753 100644
--- a/arch/arm/mach-pxa/Kconfig
+++ b/arch/arm/mach-pxa/Kconfig
@@ -20,8 +20,7 @@
 
 endif
 
-choice
-	prompt "Select target board"
+menu "Select target boards"
 
 config ARCH_GUMSTIX
 	bool "Gumstix XScale boards"
@@ -138,7 +137,7 @@
 	select PXA27x
 	select IWMMXT
 
-endchoice
+endmenu
 
 choice
 	prompt "Used baseboard"