Add MemTxAttrs to the IOTLB

Add a MemTxAttrs field to the IOTLB, and allow target-specific
code to set it via a new tlb_set_page_with_attrs() function;
pass the attributes through to the device when making IO accesses.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

include/exec/cpu-defs.h

@@ -30,6 +30,7 @@
 #ifndef CONFIG_USER_ONLY
 #include "exec/hwaddr.h"
 #endif
+#include "exec/memattrs.h"
 
 #ifndef TARGET_LONG_BITS
 #error TARGET_LONG_BITS must be defined before including this header
@@ -109,6 +110,7 @@ QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
  */
 typedef struct CPUIOTLBEntry {
     hwaddr addr;
+    MemTxAttrs attrs;
 } CPUIOTLBEntry;
 
 #define CPU_COMMON_TLB \