change v6:
1. include bitfield header and fix incompatible pointer types
change v5:
1. add version change log and the previous patch link
2. change comment in msdc_cqe_cit_cal() to increase readability.
3. change the type of hclk_freq from "u64" to "unsigned long".
4. don't open code FIELD_GET.
change v4:
1. remove else case in msdc_cqe_cit_cal() function due to it doesn't need.
2. fix build error.
change v3:
1. add msdc_cqe_cit_cal() function to calculate the CIT value.
change v2:
1. add more comments.