x86: clean up old gcc warnings

gcc 3.2.2 reports:

In file included from /usr/src/all/linux-next/arch/x86/include/asm/page.h:8,
                 from /usr/src/all/linux-next/arch/x86/include/asm/processor.h:18,
                 from /usr/src/all/linux-next/arch/x86/include/asm/atomic_32.h:6,
                 from /usr/src/all/linux-next/arch/x86/include/asm/atomic.h:2,
                 from include/linux/crypto.h:20,
                 from arch/x86/kernel/asm-offsets_32.c:7,
                 from arch/x86/kernel/asm-offsets.c:2:
/usr/src/all/linux-next/arch/x86/include/asm/page_types.h:54: warning: parameter has incomplete type
/usr/src/all/linux-next/arch/x86/include/asm/page_types.h:56: warning: parameter has incomplete type
In file included from /usr/src/all/linux-next/arch/x86/include/asm/page.h:8,
                 from /usr/src/all/linux-next/arch/x86/include/asm/processor.h:18,
                 from include/linux/prefetch.h:14,
                 from include/linux/list.h:6,
                 from include/linux/module.h:9,
                 from init/main.c:13:
/usr/src/all/linux-next/arch/x86/include/asm/page_types.h:54: warning: parameter has incomplete type
/usr/src/all/linux-next/arch/x86/include/asm/page_types.h:56: warning: parameter has incomplete type

This is a bogus warning, but moving the pat-related functions
into asm/pat.h and including asm/pgtable_types.h should fix it.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reported-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/include/asm/page_types.h

@@ -40,14 +40,8 @@
 
 #ifndef __ASSEMBLY__
 
-struct pgprot;
-
 extern int page_is_ram(unsigned long pagenr);
 extern int devmem_is_allowed(unsigned long pagenr);
-extern void map_devmem(unsigned long pfn, unsigned long size,
-		       struct pgprot vma_prot);
-extern void unmap_devmem(unsigned long pfn, unsigned long size,
-			 struct pgprot vma_prot);
 
 extern unsigned long max_low_pfn_mapped;
 extern unsigned long max_pfn_mapped;

arch/x86/include/asm/pat.h

@@ -2,6 +2,7 @@
 #define _ASM_X86_PAT_H
 
 #include <linux/types.h>
+#include <asm/pgtable_types.h>
 
 #ifdef CONFIG_X86_PAT
 extern int pat_enabled;
@@ -17,5 +18,9 @@ extern int free_memtype(u64 start, u64 end);
 
 extern int kernel_map_sync_memtype(u64 base, unsigned long size,
 		unsigned long flag);
+extern void map_devmem(unsigned long pfn, unsigned long size,
+		       struct pgprot vma_prot);
+extern void unmap_devmem(unsigned long pfn, unsigned long size,
+			 struct pgprot vma_prot);
 
 #endif /* _ASM_X86_PAT_H */