arm/debug_console: Ensure we always return before newlines

* Similar to what riscv64 does
* Solves incorrect newlines
                            in qemu serial.

Change-Id: Ib1179728529dd4bf51c8361fdb6190bd43ccb851
Reviewed-on: https://review.haiku-os.org/c/haiku/+/4895
Reviewed-by: <[email protected]>
Reviewed-by: Alex von Gluck IV <[email protected]>

src/system/kernel/arch/arm/arch_debug_console.cpp

@@ -83,7 +83,12 @@ void
 arch_debug_serial_puts(const char *s)
 {
 	while (*s != '\0') {
-		arch_debug_serial_putchar(*s);
+		char ch = *s;
+		if (ch == '\n') {
+			arch_debug_serial_putchar('\r');
+			arch_debug_serial_putchar('\n');
+		} else if (ch != '\r')
+			arch_debug_serial_putchar(ch);
 		s++;
 	}
 }