ARM: dts: imx6dl-yapp43: Add support for new HW revision of the IOTA board

The PCB used for all the current boards (Ursa, Draco, Hydra, Orion, Crux)
was slightly redesigned and delivers some new features while some unused
components were removed.

- External RTC chip with supercap added.
- Secure element added.
- LCD display power supply enable/disable signal added.
- Touch keyboard reset and interrupt signals added.
- Factory reset GPIO button added.
- Audio codec LM49350 (EoL) removed and replaced by PWM audio output.
- QCA8334 switch was replaced by Marvell 88E6141.
- PCIe completely removed.
- uSD card removed and replaced by board-to-board expansion connector.

There are four configuration variants of the new board:

1. Pegasus
The board configuration is based on Orion with the following major changes:

- Quad core SoC
- 4GB of RAM
- RTC with supercap added
- Secure element added

2. Pegasus+
This is the very same board as Pegasus but uses the i.MX6QuadPlus SoC.

3. Lynx
The board configuration is based on Draco with the following major changes:

- DualLite SoC
- 1GB of RAM
- RTC with supercap added
- Secure element added

4. Phoenix
The board configuration is based on Ursa with the following major changes:

- DualLite Soc
- 1GB of RAM
- RTC with supercap added
- Secure element added
- LCD display support removed
- UART2 removed
- Factory reset GPIO button added

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>