all-archs: consolidate .data section definition in asm-generic

With this consolidation we can now modify the .data
section definition in one spot for all archs.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
diff --git a/arch/alpha/kernel/vmlinux.lds.S b/arch/alpha/kernel/vmlinux.lds.S
index ab60e81..449e76f 100644
--- a/arch/alpha/kernel/vmlinux.lds.S
+++ b/arch/alpha/kernel/vmlinux.lds.S
@@ -89,7 +89,7 @@
 
   _data = .;
   .data : {					/* Data */
-	*(.data)
+	DATA_DATA
 	CONSTRUCTORS
   }