x86: add X86_64 dependency to x86_64 specific symbols in Kconfig.x86_64
x86: add X86_64 dependency to x86_64 specific symbols in Kconfig.x86_64

To ease unification of Kconfig.i386 and Kconfig.x86_64
add X86_64 dependencies to all x86_64 specific symbols.

This patch introduce no functional changes but is one step
towards unification. This smaller step is used to ease
review of the patch set.

Signed-off-by: Sam Ravnborg <f16bed56189e249fe4ca8ed10a1ecae60e8ceac0@ravnborg.org>
Cc: Thomas Gleixner <00e4cf8f46a57000a44449bf9dd8cbbcc209fd2a@linutronix.de>
Cc: Ingo Molnar <9dbbbf0688fedc85ad4da37637f1a64b8c718ee2@redhat.com>
Cc: "H. Peter Anvin" <8a453bad9912ffe59bc0f0b8abe03df9be19379e@zytor.com>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas