drm/amdgpu/nbio7.7: fix IP version check

Use the helper function rather than reading it directly.

Reviewed-by: Yang Wang <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/amdgpu/nbio_v7_7.c

···
 	if (def != data)
 		WREG32_SOC15(NBIO, 0, regBIF0_PCIE_MST_CTRL_3, data);
 
-	switch (adev->ip_versions[NBIO_HWIP][0]) {
+	switch (amdgpu_ip_version(adev, NBIO_HWIP, 0)) {
 	case IP_VERSION(7, 7, 0):
 		data = RREG32_SOC15(NBIO, 0, regRCC_DEV0_EPF5_STRAP4) & ~BIT(23);
 		WREG32_SOC15(NBIO, 0, regRCC_DEV0_EPF5_STRAP4, data);