auxdisplay: arm-charlcd: Fix struct charlcd doc line

There was a missing first line and a missing member,
which gave a warning under W=1:

    CC      drivers/auxdisplay/arm-charlcd.o
  drivers/auxdisplay/arm-charlcd.c:57: warning: Cannot understand
   * @dev: a pointer back to containing device on line 57 - I thought
  it was a doc line

Cc: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>