x86/Kconfig: Update lists in X86_EXTENDED_PLATFORM

The order of the entries matches the order they appear in Kconfig.

In 2011, AMD Elan was moved to Kconfig.cpu and the dependency on
X86_EXTENDED_PLATFORM was dropped in:

  ce9c99af ("x86, cpu: Move AMD Elan Kconfig under "Processor family"")

Support for Moorestown MID devices was removed in 2012 in:

  1a8359e4 ("x86/mid: Remove Intel Moorestown")

SGI 320/540 (Visual Workstation) was removed in 2014 in:

  c5f9ee3d ("x86, platforms: Remove SGI Visual Workstation")

Signed-off-by: Mateusz Jończyk <mat.jonczyk@o2.pl>
Signed-off-by: David Heideberg <david@ixit.cz>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250321-x86_x2apic-v3-4-b0cbaa6fa338@ixit.cz