shift-axolotl: new device

This adds basic support for a new device, SHIFT6mq (axolotl).

Specs are attached below. This port allows to boot pmos and access it via ssh.

There is no graphical bringup yet.

---

Specifications

Basic	Spec Sheet
Chipset	Qualcomm® Snapdragon™ 845
CPU	4x ARM Cortex-A75, 4x ARM Cortex-A55 (64 bit)
GPU	Adreno 630
Memory	8 GB RAM LPDDR4X (SK Hynix)
MicroSD	Up to 512 GB
Storage	128 GB UFS 2.1
----------	--------------------------------------------------------------
Battery	Li-Ion 3850 mAh battery
Camera	Back: 16 MP Sony IMX519 + 24 MP Samsung S5K2X7SP
Camera	Front: 16 MP Samsung S5K3P9SP04-FGX9
Display	AMOLED, 1080 x 2160 pixels, 6 inches (~402 ppi pixel density)
----------	--------------------------------------------------------------
Bluetooth	5.0
Dual SIM	Yes
NFC	Supported
----------	--------------------------------------------------------------
Software	Initial launch with Android™ 10

Advanced	Spec Sheet
Display	DP over USB-C supported