GenWQE: Change default access rights for device node

Since it should always be ok for normal users to operate the accelerator,
it makes sense to change it in our driver, rather than adding udev rules
for all Linux distributions.

Signed-off-by: Frank Haverkamp <haver@linux.vnet.ibm.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>