Drop jerry_port_putchar

Recent changes eliminate the need for `jerry_port_putchar`. As port
API discussions don't make it likely that it will ever be needed
again, this patch removes its declaration from jerry-port.h and its
implementations from the port(s).

The related code in jerry-libc is not needed either: whatever `putc`
(and `puts`) can do, `printf` can do as well.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-libc/target/mcu-stubs/jerry-libc-target.c

@@ -24,13 +24,6 @@
 
 #include "jerry-libc-defs.h"
 
-/** Output of character. Writes the character c, cast to an unsigned char, to stdout.  */
-int
-putchar (int c __attr_unused___)
-{
-  return 1;
-} /* putchar */
-
 /** exit - cause normal process termination  */
 void __attr_noreturn___ __attr_used___
 exit (int status __attr_unused___)