Revert "drm/amdgpu: Report vbios version instead of PN"

This reverts commit 7748ce5b.

vbios_version sysfs node is used to identify Part Number also. Revert to
the same so that it doesn't break scripts/software which parse this.
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1776,7 +1776,7 @@ static ssize_t amdgpu_atombios_get_vbios_version(struct device *dev,
 	struct amdgpu_device *adev = drm_to_adev(ddev);
 	struct atom_context *ctx = adev->mode_info.atom_context;
 
-	return sysfs_emit(buf, "%s\n", ctx->vbios_ver_str);
+	return sysfs_emit(buf, "%s\n", ctx->vbios_pn);
 }
 
 static DEVICE_ATTR(vbios_version, 0444, amdgpu_atombios_get_vbios_version,