m68knommu: fix undefined reference to `mach_get_rtc_pll'

Configuring for a nommu classic m68k target and enabling the generic rtc
driver (CONFIG_RTC_DRV_GENERIC) will result in the following compile
error:

   m68k-linux-ld: arch/m68k/kernel/time.o: in function `rtc_ioctl':
   time.c:(.text+0x82): undefined reference to `mach_get_rtc_pll'
   m68k-linux-ld: time.c:(.text+0xbc): undefined reference to `mach_set_rtc_pll'
   m68k-linux-ld: time.c:(.text+0xf4): undefined reference to `mach_set_rtc_pll'

There are no definitions of "mach_set_rtc_pll" and "mach_get_rtc_pll" in the
nommu code paths. Move these definitions and the associated "mach_hwclk",
so that they are around their use case in time.c. This means they will
always be defined on the builds that require them, and not on those that
cannot use them - such as ColdFire (both with and without MMU enabled).
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>

arch/m68k/kernel/setup_mm.c

@@ -87,15 +87,8 @@ void (*mach_sched_init) (void) __initdata = NULL;
 void (*mach_init_IRQ) (void) __initdata = NULL;
 void (*mach_get_model) (char *model);
 void (*mach_get_hardware_list) (struct seq_file *m);
-/* machine dependent timer functions */
-int (*mach_hwclk) (int, struct rtc_time*);
-EXPORT_SYMBOL(mach_hwclk);
 unsigned int (*mach_get_ss)(void);
-int (*mach_get_rtc_pll)(struct rtc_pll_info *);
-int (*mach_set_rtc_pll)(struct rtc_pll_info *);
 EXPORT_SYMBOL(mach_get_ss);
-EXPORT_SYMBOL(mach_get_rtc_pll);
-EXPORT_SYMBOL(mach_set_rtc_pll);
 void (*mach_reset)( void );
 void (*mach_halt)( void );
 void (*mach_power_off)( void );

arch/m68k/kernel/setup_no.c

@@ -50,7 +50,6 @@ char __initdata command_line[COMMAND_LINE_SIZE];
 
 /* machine dependent timer functions */
 void (*mach_sched_init)(void) __initdata = NULL;
-int (*mach_hwclk) (int, struct rtc_time*);
 
 /* machine dependent reboot functions */
 void (*mach_reset)(void);

arch/m68k/kernel/time.c

@@ -63,6 +63,15 @@ void timer_heartbeat(void)
 #endif /* CONFIG_HEARTBEAT */
 
 #ifdef CONFIG_M68KCLASSIC
+/* machine dependent timer functions */
+int (*mach_hwclk) (int, struct rtc_time*);
+EXPORT_SYMBOL(mach_hwclk);
+
+int (*mach_get_rtc_pll)(struct rtc_pll_info *);
+int (*mach_set_rtc_pll)(struct rtc_pll_info *);
+EXPORT_SYMBOL(mach_get_rtc_pll);
+EXPORT_SYMBOL(mach_set_rtc_pll);
+
 #if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC)
 void read_persistent_clock64(struct timespec64 *ts)
 {