drm/amd/display: Initialize denominators' default to 1

[WHAT & HOW]
Variables used as denominators and maybe not assigned to other values,
should not be 0. Change their default to 1 so they are never 0.

This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20.c

@@ -78,7 +78,7 @@ static void calculate_ttu_cursor(struct display_mode_lib *mode_lib,
 
 static unsigned int get_bytes_per_element(enum source_format_class source_format, bool is_chroma)
 {
-	unsigned int ret_val = 0;
+	unsigned int ret_val = 1;
 
 	if (source_format == dm_444_16) {
 		if (!is_chroma)

drivers/gpu/drm/amd/display/dc/dml/dml1_display_rq_dlg_calc.c

@@ -39,7 +39,7 @@
 
 static unsigned int get_bytes_per_element(enum source_format_class source_format, bool is_chroma)
 {
-	unsigned int ret_val = 0;
+	unsigned int ret_val = 1;
 
 	if (source_format == dm_444_16) {
 		if (!is_chroma)

drivers/gpu/drm/amd/display/dc/dml2/dml21/src/dml2_core/dml2_core_shared.c

@@ -9386,8 +9386,8 @@ static void CalculateVMGroupAndRequestTimes(
 	double TimePerVMRequestVBlank[],
 	double TimePerVMRequestFlip[])
 {
-	unsigned int num_group_per_lower_vm_stage = 0;
-	unsigned int num_req_per_lower_vm_stage = 0;
+	unsigned int num_group_per_lower_vm_stage = 1;
+	unsigned int num_req_per_lower_vm_stage = 1;
 
 #ifdef __DML_VBA_DEBUG__
 	dml2_printf("DML::%s: NumberOfActiveSurfaces = %u\n", __func__, NumberOfActiveSurfaces);