target-sparc: move common cpu initialisation routines to sparc64.c

Signed-off-by: Artyom Tarasenko <atar4qemu@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>

include/hw/sparc/sparc64.h

@@ -0,0 +1,5 @@
+
+SPARCCPU *sparc64_cpu_devinit(const char *cpu_model,
+                              const char *dflt_cpu_model, uint64_t prom_addr);
+
+void sparc64_cpu_set_ivec_irq(void *opaque, int irq, int level);