drm/amdgpu: Refactor 'amdgpu_connector_dvi_detect' in amdgpu_connectors.c

Fixes the below:

WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
WARNING: Missing a blank line after declarations
WARNING: Too many leading tabs - consider code refactoring
+                                               if (list_connector->connector_type != DRM_MODE_CONNECTOR_VGA) {
WARNING: Too many leading tabs - consider code refactoring
+                                                       if (!amdgpu_display_hpd_sense(adev, amdgpu_connector->hpd.hpd)) {

Cc: Guchun Chen <guchun.chen@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>