board: gw_ventana: gsc: fix GSC read/write functions

commit 7c84319a ("dm: gpio: Correct use of -ENODEV in drivers")
changed the return code for an I2C NAK from -ENODEV to -EREMOTEIO.

Update the gsc_i2c_read and gsc_i2c_write functions for this change
to properly retry the transaction on a NAK meaning the GSC is busy.

Fixes: 7c84319a ("dm: gpio: Correct use of -ENODEV in drivers")
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>