arm64: dts: Add the arasan mmc DTS entries for APM X-Gene v1 SoC

This patch adds the arasan mmc nodes to reuse the of-arasan
driver for APM X-Gene v1 SoC platforms.

[dhdang: changelog]
Signed-off-by: Suman Tripathi <stripathi@apm.com>
Signed-off-by: Duc Dang <dhdang@apm.com>