powerpc: Do not use the ATB for e500 multilib

The e500v1 has no support for the ATB.

Update #2369.

c/src/lib/libbsp/powerpc/qoriq/startup/bspstart.c

@@ -90,7 +90,13 @@ void bsp_start(void)
     BSP_bus_frequency = bsp_uboot_board_info.bi_busfreq
       / QORIQ_BUS_CLOCK_DIVIDER;
     bsp_clicks_per_usec = BSP_bus_frequency / 8000000;
-    rtems_counter_initialize_converter(bsp_uboot_board_info.bi_intfreq);
+    rtems_counter_initialize_converter(
+      #ifdef __PPC_CPU_E6500__
+        bsp_uboot_board_info.bi_intfreq
+      #else
+        BSP_bus_frequency / 8
+      #endif
+    );
   #endif /* HAS_UBOOT */
 
   /* Initialize some console parameters */

cpukit/score/cpu/powerpc/rtems/score/cpu.h

@@ -838,7 +838,7 @@ static inline CPU_Counter_ticks _CPU_Counter_read( void )
 {
   CPU_Counter_ticks value;
 
-#if defined(ppc8540) || defined(__PPC_CPU_E6500__)
+#if defined(__PPC_CPU_E6500__)
   /* Use Alternate Time Base */
   __asm__ volatile( "mfspr %0, 526" : "=r" (value) );
 #else