ARM: tegra: colibri: Fix HDMI supplies

Fix HDMI supplies (both regular VDD as well as PLL ones) being switched
by the TPS65911 PMIC's GPIO6 aka EN_VDD_HDMI by introducing two new GPIO
witched fixed regulators avdd_hdmi_pll_1v8_reg and avdd_hdmi_3v3_reg.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>