drm/amdgpu/gfx9: Fix incorrect firmware size calculation

[WHY]
The memcpy() function copies n bytes from memory area src to memory area
dest. So specify the firmware size in bytes.

[How]
Correct the calculation.
Acked-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Lei Guo <raykwok1150@163.com>
Reviewed-by: Junwei Zhang <zjunweihit@163.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gfx_v9_0.c

@@ -1960,7 +1960,7 @@ static int gfx_v9_0_mec_init(struct amdgpu_device *adev)
 	fw_data = (const __le32 *)
 		(adev->gfx.mec_fw->data +
 		 le32_to_cpu(mec_hdr->header.ucode_array_offset_bytes));
-	fw_size = le32_to_cpu(mec_hdr->header.ucode_size_bytes) / 4;
+	fw_size = le32_to_cpu(mec_hdr->header.ucode_size_bytes);
 
 	r = amdgpu_bo_create_reserved(adev, mec_hdr->header.ucode_size_bytes,
 				      PAGE_SIZE, AMDGPU_GEM_DOMAIN_GTT,