dmaengine: stedma40: fix 'physical' typo

Fix misspelling of "physical".

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20210126205906.2918099-1-helgaas@kernel.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>