add a helper function to read kernel cmdline parameter from grubby --info
    
    Resolves: bz1895258
    Upstream: Fedora
    Conflict: None
    
    commit fb9e6838abef1e3a2ba43966f58a1f146989b148
    Author: Coiby Xu <coxu@redhat.com>
    Date:   Tue Nov 16 06:48:40 2021 +0800
    
        add a helper function to read kernel cmdline parameter from grubby --info
    
        This helper function will be used to retrieve the value of kernel
        cmdline parameters including crashkernel, fadump, swiotlb and etc.
    
        Suggested-by: Philipp Rudo <prudo@redhat.com>
        Reviewed-by: Pingfan Liu <piliu@redhat.com>
        Signed-off-by: Coiby Xu <coxu@redhat.com>
    
    Signed-off-by: Coiby Xu <coxu@redhat.com>