Use Kconfig.preempt.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -1370,14 +1370,7 @@ config NR_CPUS
 	  This is purely to save memory - each supported CPU adds
 	  approximately eight kilobytes to the kernel image.
 
-config PREEMPT
-	bool "Preemptible Kernel"
-	help
-	  This option reduces the latency of the kernel when reacting to
-	  real-time or interactive events by allowing a low priority process to
-	  be preempted even if it is in kernel mode executing a system call.
-	  This allows applications to run more reliably even when the system is
-	  under load.
+source "kernel/Kconfig.preempt"
 
 config RTC_DS1742
 	bool "DS1742 BRAM/RTC support"