drm/i915: Move a bunch of stuff into rodata from the stack

Toss a bunch if constants into .rodata drom the stack. Also
shrink the types of some of the arrays to reduce the size.

bloat-o-meter -c intel_dpll_mgr.o:
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-86 (-86)
Function                                     old     new   delta
icl_get_dplls                               3393    3372     -21
skl_get_dpll                                2069    2004     -65
Total: Before=28029, After=27943, chg -0.31%
add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0)
Data                                         old     new   delta
Total: Before=17, After=17, chg +0.00%
add/remove: 2/0 grow/shrink: 0/2 up/down: 28/-129 (-101)
RO Data                                      old     new   delta
dco_central_freq                               -      24     +24
div1_vals                                      -       4      +4
odd_dividers                                  28       7     -21
even_dividers                                144      36    -108
Total: Before=3600, After=3499, chg -2.81%

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220301173128.6988-3-ville.syrjala@linux.intel.com


Reviewed-by: Jani Nikula <jani.nikula@intel.com>