s390/uaccess: always run the kernel in home space

Simplify the uaccess code by removing the user_mode=home option.
The kernel will now always run in the home space mode.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index 52b5653..9c82ceb 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -10,8 +10,11 @@
 
 #ifndef __ASSEMBLY__
 
-extern long psw_kernel_bits;
-extern long psw_user_bits;
+#define PSW_KERNEL_BITS	(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_HOME | \
+			 PSW_MASK_EA | PSW_MASK_BA)
+#define PSW_USER_BITS	(PSW_MASK_DAT | PSW_MASK_IO | PSW_MASK_EXT | \
+			 PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_MCHECK | \
+			 PSW_MASK_PSTATE | PSW_ASC_PRIMARY)
 
 /*
  * The pt_regs struct defines the way the registers are stored on