bsps/sparc: Move polled APBUART functions

This reduces the link-time dependencies and avoids copy-and-paste.

bsps/sparc/leon3/console/printk_support.c

@@ -23,7 +23,6 @@
 #include <assert.h>
 #include <stdio.h>
 #include <bsp/apbuart.h>
-#include <bsp/apbuart_termios.h>
 
 int leon3_debug_uart_index __attribute__((weak)) = 0;
 struct apbuart_regs *leon3_debug_uart = NULL;