pata_arasan_cf: remove bogus to_platform_device() calls

The suspend()/resume() methods already get the right 'struct device' to get the
driver data from -- there's no need to get to the 'struct platform_device' that
contains that 'struct device' just to call dev_get_drvdata()...

Acked-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>