leeco-le2: new kernel and progress on support

This adds and renews basic support for LeEco Le2

This is for the snapdragon X52x models.

Works:

• flashing with fastboot
• kernel boots
• ssh over USB and wifi
• USB Internet
• framebuffer (pmOS splash screens, weston)
• wayland-based UIs ?
• touchscreen (tested)
• battery (tested)
• wifi (tested)
• audio (tested, partially implemented and needs work)

Does not work:

• osk-sdl and therefore charging-sdl
• camera (not tested)
• modem (not tested)
• everything else