ARM: tegra: allow pinmux mux option not to be set by init tables

Define enum PMUX_FUNC_DEFAULT, which indicates that a table entry passed
to pinmux_config_pingrp()/pinmux_config_pingrp_table() shouldn't change
the mux option in HW.

For pins that will be used as GPIOs, the mux option is irrelevant, so we
simply don't want to define any mux option in the pinmux initialization
table.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
ARM: tegra: add GPIO initialization table function

The HW-defined procedure for booting Tegra requires that some pins be
set up as GPIOs immediately at boot in order to avoid glitches on those
pins, when the pinmux is programmed. Add a feature to the GPIO driver
which executes a GPIO configuration table. Board files will use this to
implement the correct HW initialization procedure.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
ARM: tegra: add function to enable input clamping on tristate

The HW-defined procedure for booting Tegra requires that
CLAMP_INPUTS_WHEN_TRISTATED be enabled before programming the pinmux.
Add a function to the pinmux driver to allow boards to do this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
ARM: tegra: make use of GPIO init table on Jetson TK1

The HW-defined procedure for booting Tegra requires that some pins be
set up as GPIOs immediately at boot in order to avoid glitches on those
pins, when the pinmux is programmed. This patch implements this
procedure for Jetson TK1. For pins which are to be used as GPIOs, the
pinmux mux function need not be programmed, so the pinmux table is also
adjusted.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
ARM: tegra: clamp inputs on Jetson TK1

The HW-defined procedure for booting Tegra requires that
CLAMP_INPUTS_WHEN_TRISTATED be enabled before programming the pinmux.
Modify the Jetson TK1 board to do this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>