at91: add support for sama5d27-wlsom1-ek board

at91: add support for sama5d27-wlsom1-ek board

Add support for SAMA5D27 WLSOM1-EK board.

Hardware:
- SIP: SAMA5D27C-LD2G-CU including SAMA5D27 MPU and 2Gbit LPDDR2-SDRAM
- MMC: one standard SD card interface
- Flash: 64 Mb serial quad I/O flash memory (SST26VF064BEUIT-104I/MF)
	 with embedded EUI-48 and EUI-64 MAC addresses
- USB: one USB device, one USB host one HSIC interface
- Ethernet: 1x10/100Mbps port
- WiFi/BT: IEEE 802.11 b/g/n Wi-Fi plus Bluetooth (Wi-Fi/BT) module
	   (ATWILC3000-MR110UA)
- Crypto: one ATECC608B-TNGTLS secure element
- Video: one LCD RGB 18-bit interface, one ISC 12-bit camera interface
- Debug port: one JTAG interface, one UART interface, one WILC UART
              interface
- Leds: one RGB LED
- Buttons: start, reset, wakeup, user buttons
- Expansion: one tamper connector, one mikrobus interface, 2 XPRO PTC
             connector
- Power managament: PMIC (MCP16502)

Flashing:
- follow procedure at [1]

[1] https://www.linux4sam.org/bin/view/Linux4SAM/Sama5d27WLSom1EKMainPage#Create_a_SD_card_with_the_demo

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>