Remove all traces of __powerpc__

According to $GCC/gcc/config/rs6000/rs6000-c.c _ARCH_PPC is the
ubiquitous define which should be used to test whether gcc targets
PowerPC, on 64bit platforms _ARCH_PPC64 will be also defined.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6301 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/bsd-user/elfload.c b/bsd-user/elfload.c
index a045529..82f172c 100644
--- a/bsd-user/elfload.c
+++ b/bsd-user/elfload.c
@@ -12,7 +12,7 @@
 #include "qemu.h"
 #include "disas.h"
 
-#ifdef __powerpc64__
+#ifdef _ARCH_PPC64
 #undef ARCH_DLINFO
 #undef ELF_PLATFORM
 #undef ELF_HWCAP