remove PREEMPT here, make it choosable via menu later

target/arm/kernel/raspberry-pi

@@ -2,9 +2,6 @@ CONFIG_ARM=y
 CONFIG_FIQ=y
 CONFIG_ARM_PATCH_PHYS_VIRT=y
 CONFIG_KUSER_HELPERS=y
-CONFIG_PREEMPT=y
-CONFIG_TREE_PREEMPT_RCU=y
-CONFIG_PREEMPT_RCU=y
 CONFIG_ARCH_BCM2708=y
 CONFIG_MACH_BCM2708=y
 CONFIG_BCM2708_GPIO=y