drivers: remote_pager: introduce remote_pager module for gmem

euleros inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I7WLVX



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Introduce remote_pager, an extension module for GMEM,
which can be used for communication between the remote and host

Signed-off-by: Cunshu Ni <nicunshu@huawei.com>