Move hw/arm related sources

hw/boards.h, hw/devices.h -> include/hw/
hw/arm_pic.c -> hw/arm/pic.c

Change-Id: If2a0ac71e44b13e792704ff36885667709ac331a
diff --git a/Makefile.target b/Makefile.target
index c69791e..b8a3e4c 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -91,13 +91,14 @@
 
 
 ifeq ($(EMULATOR_TARGET_ARCH),arm)
-HW_SOURCES += android_arm.c \
-    arm_pic.c \
+HW_SOURCES += \
+    android_arm.c \
+    arm/pic.c \
+    arm/boot.c \
     goldfish_interrupt.c \
     goldfish_switch.c \
     goldfish_timer.c \
     goldfish_trace.c \
-    arm/boot.c
 
 # The following sources must be compiled with the final executables
 # because they contain device_init() or machine_init() statements.