defconfig: veyron: no need for CONFIG_SPL_PINCTRL_FULL

Veyrons do not need full pinctrl support for SPL.
The full pinctrl support does nothing when enabled with OF_PLATDATA,
thus was already unused.
This frees about 4kB of SPL size.

Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>