The Stingray SoC has two instances of SDHCI controller
and one instance of iProc PWM.

Let's enable above mentioned devices in Stingray DT.
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: Anup Patel <anup.patel@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>