thermal: armada: Use msleep for long delays

Use msleep for long (> 10ms) delays, instead of the busy waiting mdelay.
All delays are called from the probe routine, where scheduling is
allowed.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>