Move parts of dcn20 code that uses FPU to dml folder. It aims to isolate
FPU operations as described by series:

drm/amd/display: Introduce FPU directory inside DC
https://patchwork.freedesktop.org/series/93042/

This patch moves the following functions from dcn20_resource to
dml/dcn20_fpu and calls of public functions in dcn20_resource are
wrapped by DC_FP_START/END():

- void dcn20_populate_dml_writeback_from_context
- static bool is_dtbclk_required()
- static enum dcn_zstate_support_state()
- void dcn20_calculate_dlg_params()
- static void swizzle_to_dml_params()
- int dcn20_populate_dml_pipes_from_context()
- void dcn20_calculate_wm()
- void dcn20_cap_soc_clocks()
- void dcn20_update_bounding_box()
- void dcn20_patch_bounding_box()
- bool dcn20_validate_bandwidth_fp()

This movement also affects dcn21/30/31, as dcn20_calculate_dlg_params()
is used by them. For this reason, I included dcn20_fpu headers in
dcn20_resource headers to make dcn20_calculate_dlg_params() visible to
dcn21/30/31.

Three new functions are created to isolate well-delimited FPU
operations:

- void dcn20_fpu_set_wb_arb_params(): set cli_watermark,
  pstate_watermark and time_per_pixel from wb_arb_params (struct
mcif_arb_params), since those uses FPU operations on double types:
WritebackUrgentWatermark, WritebackDRAMClockChangeWatermark, '16.0'.
- void dcn20_fpu_set_wm_ranges(): set min_fill_clk_mhz and
  max_fill_clk_mhz involves FPU calcs on dram_speed_mts (double type);
- void dcn20_fpu_adjust_dppclk(): adjust operation on RequiredDPPCLK
  that is a double.
Signed-off-by: Melissa Wen <mwen@igalia.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>