[S390] rename lowcore field

The 16 bit value at the lowcore location with offset 0x84 is the
cpu address that is associated with an external interrupt. Rename
the field from cpu_addr to ext_cpu_addr to make that clear.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index 6e6a72e..530ae0e 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -78,7 +78,7 @@
 	BLANK();
 	/* lowcore offsets */
 	DEFINE(__LC_EXT_PARAMS, offsetof(struct _lowcore, ext_params));
-	DEFINE(__LC_CPU_ADDRESS, offsetof(struct _lowcore, cpu_addr));
+	DEFINE(__LC_EXT_CPU_ADDR, offsetof(struct _lowcore, ext_cpu_addr));
 	DEFINE(__LC_EXT_INT_CODE, offsetof(struct _lowcore, ext_int_code));
 	DEFINE(__LC_SVC_ILC, offsetof(struct _lowcore, svc_ilc));
 	DEFINE(__LC_SVC_INT_CODE, offsetof(struct _lowcore, svc_code));