x86/Voyager: remove NATSEMI Kconfig quirk

x86/Voyager has this quirk for SCx200 support:

 config SCx200
 	tristate "NatSemi SCx200 support"
	depends on !X86_VOYAGER

Remove it - Voyager users can disable drivers they dont need.

Signed-off-by: Ingo Molnar <mingo@elte.hu>