[x86 setup] Make struct ist_info cross-architecture, and use in setup code

Make "struct ist_info" valid on both i386 and x86-64, and use the
structure by name in the setup code.  Additionally, "Intel SpeedStep
IST" is redundant, refer to it as IST consistently.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/include/asm-i386/ist.h b/include/asm-i386/ist.h
index d13d1e6..ef2003e 100644
--- a/include/asm-i386/ist.h
+++ b/include/asm-i386/ist.h
@@ -19,11 +19,13 @@
 
 #ifdef __KERNEL__
 
+#include <linux/types.h>
+
 struct ist_info {
-	unsigned long	signature;
-	unsigned long	command;
-	unsigned long	event;
-	unsigned long	perf_level;
+	u32 signature;
+	u32 command;
+	u32 event;
+	u32 perf_level;
 };
 
 extern struct ist_info ist_info;