powerpc: move ASM_CONST and stringify_in_c() into asm-const.h

This patch moves ASM_CONST() and stringify_in_c() into
dedicated asm-const.h, then cleans all related inclusions.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: asm-compat.h should include asm-const.h]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 61d15ce..8418d83 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -5,8 +5,8 @@
 
 #include <linux/types.h>
 
-#include <asm/asm-compat.h>
 #include <asm/feature-fixups.h>
+#include <asm/asm-const.h>
 
 /*
  * MMU features bit definitions