Add initial support for the MakerLisp eZ80 board. Ref: https://makerlisp.com/

Squashed commit of the following:

    configs/makerlisp:  Update comments about use of serial console.

    configs/makerlisp:  Add LED support, remove vestiges of button support (the board has no user buttons).  Add support for SPI-based MMC/SD card slot.

    arch/z80/src/ez80:  Fix some link problems.

    libs/libc/syslog/lib_syslog.c:  The ZDS-II toolchain does not declare va_coy in stdarg.h.  I think that the use of va_copy in vsyslog() is no necessary.

    configs/makerlisp:  Initial configuration directories cloned from ez80f910200zco with little more than naming changes.

libs/libc/syslog/lib_syslog.c

@@ -66,8 +66,6 @@
 
 void vsyslog(int priority, FAR const IPTR char *fmt, va_list ap)
 {
-  va_list copy;
-
   /* Check if this priority is enabled */
 
   if ((g_syslog_mask & LOG_MASK(priority)) != 0)
@@ -76,11 +74,10 @@ void vsyslog(int priority, FAR const IPTR char *fmt, va_list ap)
        *
        * NOTE:  The va_list parameter is passed by reference.  That is
        * because the va_list is a structure in some compilers and passing
-       * of structures in the NuttX sycalls does not work.
+       * of structures in the NuttX syscalls does not work.
        */
 
-      va_copy(copy, ap);
-      (void)nx_vsyslog(priority, fmt, &copy);
+      (void)nx_vsyslog(priority, fmt, &ap);
     }
 }