sparc: add leon (at697) machine

Part of K104-004.

--- merged with ---

Add plug-ins and GNATbus to leon

--- merged with ---

Add HostFs device to leon

2019-03-24  KONRAD Frederic  <konrad@adacore.com>
    * hw/sparc/leon.c: fix load_elf parameters.
2019-02-01  KONRAD Frederic  <konrad@adacore.com>
    * hw/sparc/leon.c: drop plugin.
2018-06-08  KONRAD Frederic  <konrad@adacore.com>
    * hw/sparc/leon.c: fixed against serial_hds disparition
2018-04-06  KONRAD Frederic  <konrad@adacore.com>
    * hw/sparc/leon.c: Use cpu_type instead of cpu_model which has been
                       dropped.
2018-02-12  KONRAD Frederic  <konrad@adacore.com>
    * hw/sparc/leon.c: Update to new Chardev API.
    * hw/sparc/leon.c: Update to hostfs, gnatbus, plugin source
                       reorganization.
    * hw/sparc/leon.c: Update leon2_intctl_ack prototype.

Change-Id: I594757ad137370479b152e5de8de7be7caf9a911

Author: Fabien-Chouteau

hw/sparc/Makefile.objs

@@ -1,3 +1,4 @@
 obj-$(CONFIG_SUN4M) += sun4m_iommu.o
 obj-$(CONFIG_SUN4M) += sun4m.o
 obj-$(CONFIG_LEON3) += leon3.o
+obj-y += leon.o