examples/hidkbd: follow the byte stream option rename

The example gated its decoding on HIDKBD_ENCODED, which no longer
exists: the USB HID keyboard driver reports through the keyboard upper
half now, and what produces the byte stream is
INPUT_KEYBOARD_BYTESTREAM.

Left as it was, the option could never be satisfied and the example
would quietly stop decoding special keys.

Reaching the option again brings hidkbd_decode() back into the build
after a spell of being unreachable, and it uses isprint() without
including ctype.h. That is an error rather than a warning under the
-Werror the CI builds with, in the nine configurations that enable
EXAMPLES_HIDKBD, so add the include here rather than in a later commit.

Signed-off-by: Jorge Guzman <jorge.gzm@gmail.com>

examples/hidkbd/Kconfig

@@ -36,7 +36,7 @@ config EXAMPLES_HIDKBD_DEVNAME
 config EXAMPLES_HIDKBD_ENCODED
 	bool "Encode Special Keys"
 	default y
-	depends on HIDKBD_ENCODED && LIBC_KBDCODEC
+	depends on INPUT_KEYBOARD_BYTESTREAM
 	---help---
 		Decode special key press events in the user buffer.  In this case,
 		the example coded will use the interfaces defined in

examples/hidkbd/hidkbd_main.c

@@ -35,6 +35,8 @@
 #include <nuttx/usb/usbhost.h>
 
 #ifdef CONFIG_EXAMPLES_HIDKBD_ENCODED
+#  include <ctype.h>
+
 #  include <nuttx/streams.h>
 #  include <nuttx/input/kbd_codec.h>
 #endif
@@ -55,7 +57,8 @@
 #  define CONFIG_EXAMPLES_HIDKBD_DEVNAME "/dev/kbda"
 #endif
 
-#if !defined(CONFIG_HIDKBD_ENCODED) || !defined(CONFIG_LIBC_KBDCODEC)
+#if !defined(CONFIG_INPUT_KEYBOARD_BYTESTREAM) || \
+    !defined(CONFIG_LIBC_KBDCODEC)
 #  undef CONFIG_EXAMPLES_HIDKBD_ENCODED
 #endif