The omap_device_[enable|idle|shutdown] functions print a warning
when called from an invalid state.  Print the invalid state in
the warning messages.  This also uses __func__ to get the function
name.

Also, move the entire print string onto a single line to facilitate
grepping or error messages.  Recent discussions on LKML show
strong preference for grep-able code vs. strict 80 column limit.
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>