[bus][pci] move the bus manager code into a subdir

dev/bus/pci/pci_priv.h

@@ -16,5 +16,5 @@
 #include "backend/ecam.h"
 #include "backend/type1.h"
 
-#include "bus_mgr.h"
+#include "bus_mgr/bus_mgr.h"
 

dev/bus/pci/rules.mk

@@ -2,14 +2,14 @@ LOCAL_DIR := $(GET_LOCAL_DIR)
 
 MODULE := $(LOCAL_DIR)
 
-MODULE_SRCS += \
-	$(LOCAL_DIR)/bus_mgr.cpp \
-	$(LOCAL_DIR)/debug.cpp \
-	$(LOCAL_DIR)/pci.cpp \
-\
-	$(LOCAL_DIR)/backend/ecam.cpp \
-	$(LOCAL_DIR)/backend/bios32.cpp \
-	$(LOCAL_DIR)/backend/type1.cpp \
+MODULE_SRCS += $(LOCAL_DIR)/debug.cpp
+MODULE_SRCS += $(LOCAL_DIR)/pci.cpp
+
+MODULE_SRCS += $(LOCAL_DIR)/bus_mgr/bus_mgr.cpp
+
+MODULE_SRCS += $(LOCAL_DIR)/backend/ecam.cpp
+MODULE_SRCS += $(LOCAL_DIR)/backend/bios32.cpp
+MODULE_SRCS += $(LOCAL_DIR)/backend/type1.cpp
 
 MODULE_DEPS += lib/libcpp