We have two ARM PL022 SPI instances in NS2 SoC. On NS2 SVK,
one of the ARM PL022 SPI host has Silabs si3226x slic connected
to chip-select #0 whereas second ARM PL022 SPI host has Atmel
AT25 EEPROM connected to chip-select #0.

This patch adds ARM PL022, Silabs si3226x, and Atmel AT25
DT nodes in NS2 DT and NS2 SVK DT respectively.
Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>