m68knommu: fix non-mmu classic 68000 legacy timer tick selection

The family of classic 68000 parts supported when in non-mmu mode all
currently use the legacy timer support. Move the selection of that config
option, LEGACY_TIMER_TICK, into the core CPU configuration.

This fixes compilation if no specific CPU variant is selected, since
the LEGACY_TIMER_TICK option was only selected in the specific CPU
variant configurations.
Reviewed-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Ungerer <gerg@linux-m68k.org>

arch/m68k/Kconfig.cpu

@@ -46,6 +46,7 @@ config M68000
 	select GENERIC_CSUM
 	select CPU_NO_EFFICIENT_FFS
 	select HAVE_ARCH_HASH
+	select LEGACY_TIMER_TICK
 	help
 	  The Freescale (was Motorola) 68000 CPU is the first generation of
 	  the well known M68K family of processors. The CPU core as well as
@@ -97,7 +98,6 @@ config M68060
 config M68328
 	bool
 	depends on !MMU
-	select LEGACY_TIMER_TICK
 	select M68000
 	help
 	  Motorola 68328 processor support.
@@ -105,7 +105,6 @@ config M68328
 config M68EZ328
 	bool
 	depends on !MMU
-	select LEGACY_TIMER_TICK
 	select M68000
 	help
 	  Motorola 68EX328 processor support.
@@ -113,7 +112,6 @@ config M68EZ328
 config M68VZ328
 	bool
 	depends on !MMU
-	select LEGACY_TIMER_TICK
 	select M68000
 	help
 	  Motorola 68VZ328 processor support.