sptests/sp52: Reduce clock tick interval

This helps on slow simulators.

testsuites/sptests/sp52/init.c

@@ -123,6 +123,8 @@ static rtems_task Init(
 #define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
 #define CONFIGURE_APPLICATION_NEEDS_CLOCK_DRIVER
 
+#define CONFIGURE_MICROSECONDS_PER_TICK 50000
+
 #define CONFIGURE_MAXIMUM_TASKS              2
 #define CONFIGURE_MAXIMUM_TIMERS             1