klibc.inc: use x86 over-ride instead of i486/i586/i686/pentium

32bit x86 is covered by the x86 over-ride, so duplicate over-rides for
i486/i586/i686/pentium are not required.

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>