yocto-bsp: Add core2 and corei7 tune choice to x86_64

yocto-bsp: Add core2 and corei7 tune choice to x86_64

Update the x86_64 architecture bsp creator to include choices for core2
and corei7 tune files.

(From meta-yocto rev: 06a16db32eae5b2280642643009fa653dc6f7839)

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
Cc: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Paul Eggleton <paul.eggleton@intel.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Nitin Kamble <nitin.a.kamble@intel.com>
Cc: Mark Hatle <mark.hatle@windriver.com>
Cc: Bruce Ashfield <bruce.ashfield@windriver.com>
Cc: Martin Jansa <martin.jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>