board: htc: endeavoru: add One X support

The HTC One X is a touchscreen-based, slate-sized smartphone
designed and manufactured by HTC that runs the Android operating
system. The One X features a 4.7" display, an Nvidia Tegra 3
quad-core chip, 1 GB of RAM and non-extendable 32 GB of internal
storage. UART-A is default debug port.

Tested-by: Andreas Westman Dorcsak <hedmoo@yahoo.com>
Tested-by: Ion Agorria <ion@agorria.com>
Tested-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>