tune-cortexa*: Fix TUNE_FEATURES and PACKAGE_EXTRA_ARCHS for thf-neon

tune-cortexa*: Fix TUNE_FEATURES and PACKAGE_EXTRA_ARCHS for thf-neon

* all cortexa*thf-neon except cortexa8 were missing thumb feature from
  TUNE_FEATURES_tune-armv7athf-neon
* all cortexa*thf-neon except cortexa8 included cortexa9t2-vfp instead
  of cortexa9t2hf-vfp
* PACKAGE_EXTRA_ARCHS_tune-cortexa8thf-neon was including from armv7a
  -PACKAGE_EXTRA_ARCHS_tune-armv7ahf-neon
  +PACKAGE_EXTRA_ARCHS_tune-armv7athf-neon
* please do more testing for this, I'm sending this commit mostly
  because I've noticed that new a7 and a15 differ from a8 more then I've
  expected and I don't have any a7/a15 MACHINEs, feel free to extend
  http://git.openembedded.org/openembedded-core-contrib/log/?h=jansa/tune2-test
  to add and test fake a7/a15 configs

(From OE-Core rev: a207ce735b602b751467eb43e09b958e664a8e81)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>