[POWERPC] ppc: More compile fixes

This fixes a few more miscellaneous compile problems with ARCH=ppc.

1. Don't compile devres.c on ARCH=ppc, it doesn't have ioremap_flags.
2. Include <asm/irq.h> in setup.c for the __DO_IRQ_CANON definition.
3. Include <linux/proc_fs.h> in residual.c for the
   definition of create_proc_read_entry.
4. Fix xchg_ptr to be a static inline to eliminate a compiler warning.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index f1d2cdc..c71d37d 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -10,6 +10,7 @@
 obj-y			:= string.o alloc.o \
 			   checksum_$(CONFIG_WORD_SIZE).o
 obj-$(CONFIG_PPC32)	+= div64.o copy_32.o
+obj-$(CONFIG_HAS_IOMEM)	+= devres.o
 endif
 
 obj-$(CONFIG_PPC64)	+= copypage_64.o copyuser_64.o \
@@ -23,4 +24,3 @@
 endif
 
 obj-$(CONFIG_PPC_LIB_RHEAP) += rheap.o
-obj-$(CONFIG_HAS_IOMEM)	+= devres.o