printk: move printk_safe macros to printk header

euler inclusion
category: bugfix
bugzilla: 9509, https://gitee.com/openeuler/kernel/issues/I4K61K
CVE: NA

Reference: https://lore.kernel.org/lkml/20181017044843.GD1068@jagdpanzerIV/T/



-------------------------------------------------

Make printk_safe_enter_irqsave()/etc macros available to the
rest of the kernel.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
Signed-off-by: Peng Wu <wupeng58@huawei.com>
Reviewed-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Cheng Jian <cj.chengjian@huawei.com>
Reviewed-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>