Input: usbtouchscreen - use EXPERT instead of EMBEDDED for EasyTouch

Change control of TOUCHSCREEN_USB_EASYTOUCH prompt string from
EMBEDDED to EXPERT to match the rest of this Kconfig file.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>