s390: add missing header includes for type checking

Add missing include statements to make sure that prototypes match
implementation. As reported by sparse:

arch/s390/crypto/arch_random.c:18:1:
  warning: symbol 's390_arch_random_available' was not declared. Should it be static?
arch/s390/kernel/traps.c:279:13: warning:
  symbol 'trap_init' was not declared. Should it be static?
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/crypto/arch_random.c

@@ -12,6 +12,7 @@
 
 #include <linux/kernel.h>
 #include <linux/atomic.h>
+#include <linux/random.h>
 #include <linux/static_key.h>
 #include <asm/cpacf.h>
 

arch/s390/kernel/traps.c

@@ -21,6 +21,7 @@
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
+#include <linux/cpu.h>
 #include <asm/fpu/api.h>
 #include "entry.h"