npu2: Advertise correct TCE page size

The P9 NPU workbook says that only 4K/64K/16M/256M page size are supported
and in fact npu2_map_pe_dma_window() supports just these but in absence of
the "ibm,supported-tce-sizes" property Linux assumes the default P9 PHB4
page sizes - 4K/64K/2M/1G - so when Linux tries 2M/1G TCEs, we get lots of
"Unexpected TCE size" from npu2_tce_kill().

This advertises TCE page sizes so Linux could handle it correctly, i.e.
fall back to 4K/64K TCEs.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

hw/npu2.c

@@ -1802,6 +1802,11 @@ static void npu2_add_phb_properties(struct npu2 *p)
 			      NPU2_MAX_PE_NUM);
 	dt_add_property_cells(np, "ibm,opal-reserved-pe",
 			      NPU2_RESERVED_PE_NUM);
+	dt_add_property_cells(np, "ibm,supported-tce-sizes",
+			      12, // 4K
+			      16, // 64K
+			      24, // 16M
+			      28); // 256M
 
 	dt_add_property_u64s(np, "ibm,mmio-atsd",
 			MMIO_ATSD_ADDR(p->regs, 0),