x86: Drop obsolete ARCH_BOOTMEM support

x86 unconditionally uses NO_BOOTMEM so there is no use
of the HAVE_ARCH_BOOTMEM support as mm/bootmem.c is the
only file referencing this symbol.

bootmem_arch_preferred_node() is the function referred
in the mm/bootmem.c code and can thuis be dropped too.

x86 was the sole user of HAVE_ARCH_BOOTMEM - so there is
an opportunity to clean up a little in mm/bootmem.c too
if we do not expect other users to emerge.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20120406124735.GA6920@merkur.ravnborg.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/Kconfig

@@ -1255,10 +1255,6 @@ config NODES_SHIFT
 	  Specify the maximum number of NUMA Nodes available on the target
 	  system.  Increases memory reserved to accommodate various tables.
 
-config HAVE_ARCH_BOOTMEM
-	def_bool y
-	depends on X86_32 && NUMA
-
 config HAVE_ARCH_ALLOC_REMAP
 	def_bool y
 	depends on X86_32 && NUMA

arch/x86/include/asm/mmzone_32.h

@@ -61,10 +61,4 @@ static inline int pfn_valid(int pfn)
 
 #endif /* CONFIG_DISCONTIGMEM */
 
-#ifdef CONFIG_NEED_MULTIPLE_NODES
-/* always use node 0 for bootmem on this numa platform */
-#define bootmem_arch_preferred_node(__bdata, size, align, goal, limit)	\
-	(NODE_DATA(0)->bdata)
-#endif /* CONFIG_NEED_MULTIPLE_NODES */
-
 #endif /* _ASM_X86_MMZONE_32_H */