hw/arm_gic: Move CPU interface memory region setup into arm_gic_init

Remove more NVIC ifdefs by moving the code to setup the CPU interface
memory regions into the GIC specific arm_gic_init() function rather
than the gic_init() function. Rename the latter to more closely
reflect what it's now actually doing.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/hw/armv7m_nvic.c b/hw/armv7m_nvic.c
index 4c130f1..031a7fd 100644
--- a/hw/armv7m_nvic.c
+++ b/hw/armv7m_nvic.c
@@ -449,7 +449,7 @@
     s->gic.num_cpu = 1;
     /* Tell the common code we're an NVIC */
     s->gic.revision = 0xffffffff;
-    gic_init(&s->gic, s->num_irq);
+    gic_init_irqs_and_distributor(&s->gic, s->num_irq);
     /* The NVIC and system controller register area looks like this:
      *  0..0xff : system control registers, including systick
      *  0x100..0xcff : GIC-like registers