staging: gdm724x: use GFP_ATOMIC under spin lock

A spin lock is taken here so we should use GFP_ATOMIC.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>