devres: fix devm_ioremap_*() offset parameter kerneldoc description

The offset parameter in the devres devm_ioremap_*() functions kerneldoc
entries is erroneously defined as BUS offset whereas it is actually a
resource address.

Since it is actually misleading, fix the devres devm_ioremap_* offset
parameter kerneldoc entry by replacing BUS offset with a more suitable
description (ie Resource address).

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Tejun Heo <tj@kernel.org>