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.

(From OE-Core rev: f5e0a574d87b7dc6466bfe01593fab5aa13464ff)

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>

meta/conf/machine/include/x86/README

@@ -0,0 +1,24 @@
+2012/03/30 - Mark Hatle <mark.hatle@windriver.com>
+ - Initial version
+
+Most of the items for the X86 architectures are defined in the single
+arch-x86 file.
+
+Three ABIs are define, m32, mx32 and m64.
+
+The following is the list of X86 specific variables:
+
+X86ARCH32 - This is the 32-bit architecture GNU canonical arch, TUNE_ARCH.
+
+X86ARCH64 - This is the 64-bit architecture GNU canonical arch, TUNE_ARCH.
+
+The TUNE_PKGARCH is defined as follows:
+
+TUNE_PKGARCH = ${TUNE_PKGARCH_tune-${DEFAULTTUNE}}
+
+The package architecture for 32-bit targets is historical and generally
+set to to match the core compatible processor type, i.e. i386.
+
+For 64-bit architectures, the architecture is expected to end in '_64'.
+
+If the x32 ABI is used, then the _64 is further extended with a '_x32'.