Pass panel dimensions into macro-kernels.

Details:
- Modified the interfaces to the datatype-specific macro-kernels so that:
  - pd_a and pd_b are passed in (which contain the panel dimensions of
    packed panels of a and b).
  - rs_a and cs_b are no longer passed in (they were guaranteed to be 1).
- Modified implementations of datatype-specific macro-kernels so pd_a,
  pd_b, cs_a, and rs_b are used instead of cpp macros for MR, NR, PACKMR,
  and PACKNR, respectively.
- Declare temporary c matrices (ct) as being maxmr-by-maxnr, which for now
  is equivalent to being mr-by-nr. maxmr and maxnr are declared in a new
  header file bli_kernel_post_macro_defs.h.