arm64/mpam: Use fs_context to parse mount options

hulk inclusion
category: bugfix
bugzilla: 48265
CVE: NA

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Use fs_context to parse mount options, this old process parsing from
parse_rdtgroupfs_options() will be obsoleted and removed.

Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: Cheng Jian <cj.chengjian@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>