[U-Boot] [U-Boot, v2, 03/19] gpio: Use more command-specific enums values

[Philipp Tomsich]

> At present this file uses GPIO_OUTPUT and GPIO_INPUT as its sub-command
> values. These are pretty generic names. Add a 'C' suffix to avoid possible
> conflicts.
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> ---
> 
> Changes in v2: None
> 
>  cmd/gpio.c | 37 +++++++++++++++++++++++--------------
>  1 file changed, 23 insertions(+), 14 deletions(-)
> 

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>