staging: ralink-gdma: Remove incorrect author information

Lars did not write the ralink-gdma driver. Looks like his name just got
copy&pasted from another similar DMA driver. Remove his name from the
copyright and MODULE_AUTHOR.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210607100119.26983-1-lars@metafoo.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>