[S390] cleanup s390 Kconfig

Make use of def_bool and def_tristate where possible and add sensible
defaults to the config symbols where applicable. This shortens the
defconfig file by another ~40 lines.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/Kconfig.debug b/arch/s390/Kconfig.debug
index 05221b1..2b380df 100644
--- a/arch/s390/Kconfig.debug
+++ b/arch/s390/Kconfig.debug
@@ -1,8 +1,7 @@
 menu "Kernel hacking"
 
 config TRACE_IRQFLAGS_SUPPORT
-	bool
-	default y
+	def_bool y
 
 source "lib/Kconfig.debug"
 
@@ -19,7 +18,8 @@
 	  If you are unsure, say Y.
 
 config DEBUG_STRICT_USER_COPY_CHECKS
-	bool "Strict user copy size checks"
+	def_bool n
+	prompt "Strict user copy size checks"
 	---help---
 	  Enabling this option turns a certain set of sanity checks for user
 	  copy operations into compile time warnings.