Port: Make getAddrRanges const

This patch makes getAddrRanges const throughout the code base. There
is no reason why it should not be, and making it const prevents adding
any unintentional side-effects.

src/dev/arm/gic.cc

@@ -708,7 +708,7 @@ Gic::postInt(uint32_t cpu, Tick when)
 }
 
 AddrRangeList
-Gic::getAddrRanges()
+Gic::getAddrRanges() const
 {
     AddrRangeList ranges;
     ranges.push_back(RangeSize(distAddr, DIST_SIZE));

src/dev/arm/gic.hh

@@ -261,7 +261,7 @@ class Gic : public PioDevice
     /** Return the address ranges used by the Gic
      * This is the distributor address + all cpu addresses
      */
-    virtual AddrRangeList getAddrRanges();
+    virtual AddrRangeList getAddrRanges() const;
 
     /** A PIO read to the device, immediately split up into
      * readDistributor() or readCpu()

src/dev/arm/pl111.cc

@@ -746,7 +746,7 @@ Pl111::generateInterrupt()
 }
 
 AddrRangeList
-Pl111::getAddrRanges()
+Pl111::getAddrRanges() const
 {
     AddrRangeList ranges;
     ranges.push_back(RangeSize(pioAddr, pioSize));

src/dev/arm/pl111.hh

@@ -329,7 +329,7 @@ class Pl111: public AmbaDmaDevice
      *
      * @return a list of non-overlapping address ranges
      */
-    AddrRangeList getAddrRanges();
+    AddrRangeList getAddrRanges() const;
 };
 
 #endif