[SCSI] mpt fusion: kill warnings in mptbase.h on parisc64

Verified all the arches necessary select the CONFIG_64BIT symbol. This
also kills the warning (since it was using the 32-bit case) on parisc64
and mips64.
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/message/fusion/mptbase.h

@@ -923,7 +923,7 @@ extern struct proc_dir_entry	*mpt_proc_root_dir;
 /*=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=*/
 #endif		/* } __KERNEL__ */
 
-#if defined(__alpha__) || defined(__sparc_v9__) || defined(__ia64__) || defined(__x86_64__) || defined(__powerpc__)
+#ifdef CONFIG_64BIT
 #define CAST_U32_TO_PTR(x)	((void *)(u64)x)
 #define CAST_PTR_TO_U32(x)	((u32)(u64)x)
 #else