ARM: mach-shmobile: ap4evb: modify touchpanel judgment condition

Current touchpanel had below 2 issues

- LCDD2 pin which is needed for WVGA was changed to
  IRQ28_123 pin on ts_get_pendown_state

- GPIO pull up on ts_init was disabled by gpio_request
  on ts_get_pendown_state.
  This mean the return value from gpio_get_value is untrusted.

This patch solve these issues

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>