Redefine CYGNUM_HAL_INTERRUPT_RTC_RTC because of conflict with same named macro defined in hal_intr.h (Cortex-M architecture). Define some interrrupt numbers, previously reservrd. Upgrade RTC registers. [ Bugzilla 1001904 ]

/* this is a simple hello world program */
#include <stdio.h>

int main(void)
{
  printf("Hello, eCos world!\n");
  return 0;
}