arch/powerpc: add powerpc64le support

Technically, I don't forbid powerpcle support either, but I'm not sure that
there is any library/compiler support for that at the moment (though the hw
technically makes it possible).

powerpc64le needs glibc 2.19 and gcc 4.9. I haven't looked into the support
tools, but at least gdb 7.5 is too old (7.7.1 definitely has support).

Also make powerpc64 non-experimental. It's practically old at this point.

Signed-off-by: Cody P Schafer <dev@codyps.com>
[yann.morin.1998@free.fr: use ${target_endian_le} and ${target_bits_64}]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Message-Id: <64bfbbced9dd8f62e0d6.1399801945@gun>
Patchwork-Id: 347775

diff -durN ltrace-0.4.orig/Makefile.in ltrace-0.4/Makefile.in

--- ltrace-0.4.orig/Makefile.in	2008-10-26 15:34:21.000000000 +0100

+++ ltrace-0.4/Makefile.in	2008-10-26 15:37:40.000000000 +0100

@@ -5,6 +5,7 @@

 OS		:= @HOST_OS@

 ARCH		:= $(shell echo "@HOST_ARCH@" |sed -e s/i.86/i386/      \

 						   -e s/sun4u/sparc64/  \

+						   -e s/alpha.*/alpha/  \

 						   -e s/arm.*/arm/      \

 						   -e s/sa110/arm/      \

 						   -e s/ppc64/ppc/      \