f2fs: move the option parser into handle_mount_opt

In handle_mount_opt, we use fs_parameter to parse each option.
However we're still using the old API to get the options string.
Using fsparams parse_options allows us to remove many of the Opt_
enums, so remove them.

The checkpoint disable cap (or percent) involves rather complex
parsing; we retain the old match_table mechanism for this, which
handles it well.

There are some changes about parsing options:
  1. For `active_logs`, `inline_xattr_size` and `fault_injection`,
     we use s32 type according the internal structure to record the
     option's value.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
[sandeen: forward port, minor fixes and updates]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[hongbo: minor cleanup]
Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>