commit 89878f60f4 x86: lift kernel minimum CPU requirement to Pentium MMX
caused kconfig havoc. Fix this and make sure PAE is enabled even on legacy
CPUs as the minimum required CPU has been Pentium MMX for a while now and
hence PAE is supported even on the x86_legacy target.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Anything older than that isn't supported since commit f4f8f4a180,
hence also switch to Pentium MMX when building the kernel.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>