ipq40xx: add support for TP-Link Deco-M5

ipq40xx: add support for TP-Link Deco-M5

Specifications
--------------
- SoC          : Qualcomm IPQ4019
- RAM          : 256 MiB DDR3-1600 (NT5CC128M16IP)
- Flash        : 32 MiB SPI NOR
  - V1, V2     : GigaDevice GD25Q256C
  - V3         : Winbond W25Q256FV, Micron N25Q128A11
  - V320       : EON EN25QH256, XMC XM25QH256BK (with patch included)
- WLAN         : IPQ4019 On-chip
  - 2.4 GHz    : 2x2 MIMO 802.11b/g/n
  - 5 GHz      : 2x2 MIMO 802.11n/ac
- Ethernet     : QCA8072 10/100/1000BASE-T 1x WAN; 1x LAN
- UART         : 3v3 115200n, use pins under heatsink
- Buttons      : 1x Reset
- LEDs         : 1x Combined RGB LED
  - V1         : Driven by LP5521 channels (Channel 0, 1, 2?)
  - V3, V320   : Driven by GPIO Pins (Pin 28, 32, 35 Active Low)
- Bluetooth    :
  - V1, V2, V3 : CSR8811
  - V320       : AC6368A/B
- Power        : DC 12V @ 1.2A
- FCC ID       :
  - V1         : TE7M5
  - V3         : TE7M5V3
  - V320       : TE7M5V32, 2AXJ4M5V3, 2BCGWM5V3
- TFTP ID      :
  - Client     : 192.168.0.66
  - Router     : 192.168.0.11

MAC Addresses
-------------
Label   : OPAQUE partition @ 0x0008
LAN     : Label
WAN     : Label + 1
WLAN 2G : Label + 2
WLAN 5G : Label + 3

Installation
------------
1. Install TFTP server software
2. Rename the factory image to 'M5v1_tp_recovery.bin' and copy it into
   the TFTP folder
3. Connect an interface configured to 192.168.0.66/24 to the LAN port
   - Note: The LAN port is the ethernet port that is furthest away from
     the power plug
4. Press the 'reset' button down before powering up the device, holding
   for at least 10 seconds
5. Router should download the factory image, install it, and then reboot
6. Router will start up with address 192.168.1.1

Known Issues
------------
- Some devices (including some V1 and V2 devices) may have flash chips
  that are not detected, supported by, or have broken SFDP support

Signed-off-by: Bee Cadorna <r3usrlnd@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/17537
Signed-off-by: Robert Marko <robimarko@gmail.com>