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 -dur uClibc-0.9.28.1.orig/libc/sysdeps/linux/common/Makefile uClibc-0.9.28.1/libc/sysdeps/linux/common/Makefile

--- uClibc-0.9.28.1.orig/libc/sysdeps/linux/common/Makefile	2007-01-26 00:54:19.000000000 +0100

+++ uClibc-0.9.28.1/libc/sysdeps/linux/common/Makefile	2007-02-01 08:44:37.000000000 +0100

@@ -25,6 +25,10 @@

 SRCS := $(filter-out sbrk.c,$(SRCS))

 endif

+ifneq ($(strip $(UCLIBC_HAS_LFS)),y)

+SRCS := $(filter-out readahead.c,$(SRCS))

+endif

+

 ifneq ($(strip $(UCLIBC_HAS_SSP)),y)

 SRCS := $(filter-out ssp.c,$(SRCS))

 endif