software/bios/console: Call putsnonl() from puts()

puts() and putsnonl() are very similar, and can share code.
Reduce code size by making the former call the latter.

Impact for a RISC-V build:

    $ size console.o.orig console.o
       text	   data	    bss	    dec	    hex	filename
	868	      0	     12	    880	    370	console.o.orig
	832	      0	     12	    844	    34c	console.o

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

litex/soc/software/libbase/console.c

@@ -75,10 +75,7 @@ int readchar_nonblock(void)
 
 int puts(const char *s)
 {
-	while(*s) {
+	putsnonl(s);
-		putchar(*s);
-		s++;
-	}
 	putchar('\n');
 	return 1;
 }