gpu: nvgpu: Refactor PERF VFE unit

-Created ucode_perf_vfe_inf.h and moved all VFE
 interface structs and MACROs into this header
-Created nvgpu_clk_fll_get_fmargin_idx to get
 freq margin index
-Created nvgpu_vfe_var_get_s_param to read s_param
-Removed MACROs and header includes which are
 not needed

NVGPU-4448

Change-Id: I89f946d555bcbc7823665d2a5a761049f7a5e963
Signed-off-by: rmylavarapu <rmylavarapu@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2260150
GVS: Gerrit_Virtual_Submit
Reviewed-by: Mahantesh Kumbar <mkumbar@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/pmu/perf/pmu_perf.c

@@ -26,8 +26,6 @@
 #include <nvgpu/gk20a.h>
 #include <nvgpu/pmu/perf.h>
 
-#include "pmu_perf.h"
-
 int nvgpu_perf_pmu_init_pmupstate(struct gk20a *g)
 {
 	/* If already allocated, do not re-allocate */