x86: Replace ia32 with x86 when referring to the generic architecture

x86: Replace ia32 with x86 when referring to the generic architecture

ia32 implies 32bit, while these files provide descriptions for IA32,
X86_64, and X32 architectures. The term "x86" fits this used better
without resorting to using the term "Intel" which isn't quite right as
it excludes things like the tune-c3 file describing a Via CPU.

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>