powerpc: Add cxl context to device archdata

Add cxl context pointer to archdata.  We'll want to create one of these for cxl
PCI devices.  Put them here until we can get a pci_dev specific private data.

This location was suggested by benh.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/device.h

@@ -46,6 +46,9 @@ struct dev_archdata {
 #ifdef CONFIG_FAIL_IOMMU
 	int fail_iommu;
 #endif
+#ifdef CONFIG_CXL_BASE
+	struct cxl_context	*cxl_ctx;
+#endif
 };
 
 struct pdev_archdata {