drm/amd/amdgpu: Fix errors & warnings in amdgpu_vcn.c

Fix below checkpatch insisted error & warnings:

ERROR: space required before the open brace '{'
WARNING: braces {} are not necessary for any arm of this statement
+       if ((type == VCN_ENCODE_RING) && (vcn_config & VCN_BLOCK_ENCODE_DISABLE_MASK)) {
[...]
+       } else if ((type == VCN_DECODE_RING) && (vcn_config & VCN_BLOCK_DECODE_DISABLE_MASK)) {
[...]
+       } else if ((type == VCN_UNIFIED_RING) && (vcn_config & VCN_BLOCK_QUEUE_DISABLE_MASK)) {
[...]
ERROR: code indent should use tabs where possible
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
WARNING: braces {} are not necessary for single statement blocks
+               for (i = 0; i < adev->vcn.num_enc_rings; ++i) {
+                       fence[j] += amdgpu_fence_count_emitted(&adev->vcn.inst[j].ring_enc[i]);
+
ERROR: space required before the open parenthesis '('
WARNING: Missing a blank line after declarations
WARNING: please, no spaces at the start of a line
WARNING: Symbolic permissions 'S_IRUGO' are not preferred. Consider using octal permissions '0444'.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Luben Tuikov <luben.tuikov@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>