OMAP3: Devkit8000: Change lcd power pin

This patch fixes a wrongly used lcd enable pin.

The Devkit8000 uses twl4030_ledA configured as output gpio only for
the lcd enable line. twl4030_gpio.1 is used through the generic
gpio functions while ledA is used via low level twl4030 calls.

This patch removes the low level calls and use the generic gpio functions
for initialization and use of ledA. This patch also fixes a bug where the
lcd would not power down when blanking.

Further this patch fixes an indentation issue. The comment line uses
eight whitespace and is replaced with a hard tab.

gpio_request + gpio_direction_output are replaced with gpio_request_one.
The return value of gpio_request_one is used to set the value of the
gpio to -EINVAL when unsuccessful, so that gpio_is_valid can detect the
unsuccessful request. But already successful requested gpios are not freed.

Reported-by: Daniel Morsing <daniel.morsing@gmail.com>
Signed-off-by: Thomas Weber <weber@corscience.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>