util: Move source files into a src directory.

This also moves the Makefiles, which will still produce build output in
the src directory. This is to prepare for a scons based build system
which will create a separate build directory with build artifacts.

Change-Id: I7c6d325e1d0a428656b2e3070b5e942515543696
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27209
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>

util/m5/src/Makefile.aarch64

@@ -52,7 +52,7 @@ JR=jar
 #JDK_PATH=/path/to/jdk/version_number
 
 CFLAGS=-O2 -I $(JDK_PATH)/include/ -I $(JDK_PATH)/include/linux \
-       -I../../include -march=armv8-a
+       -I../../../include -march=armv8-a
 LDFLAGS=-static -L. -lm5
 
 LIB_OBJS=m5op_arm_A64.o m5_mmap.o

util/m5/src/Makefile.arm

@@ -52,7 +52,7 @@ JR=jar
 #JDK_PATH=/path/to/jdk/version_number
 
 CFLAGS=-O2 -I $(JDK_PATH)/include/ -I $(JDK_PATH)/include/linux \
-       -I../../include -march=armv7-a
+       -I../../../include -march=armv7-a
 LDFLAGS=-L. -lm5 -static
 
 LIB_OBJS=m5op_arm.o m5_mmap.o

util/m5/src/Makefile.sparc

@@ -32,7 +32,7 @@ CC=$(CROSS_COMPILE)gcc
 AS=$(CROSS_COMPILE)as
 LD=$(CROSS_COMPILE)ld
 
-CFLAGS=-O2 -m64 -I../../include
+CFLAGS=-O2 -m64 -I../../../include
 OBJS=m5.o m5op_sparc.o m5_mmap.o
 
 all: m5

util/m5/src/Makefile.thumb

@@ -46,7 +46,7 @@ LD=$(CROSS_COMPILE)ld
 AR=$(CROSS_COMPILE)ar
 
 #CFLAGS=-O2 -march=armv7 -mthumb -I../../include
-CFLAGS=-O2 -mthumb -I../../include
+CFLAGS=-O2 -mthumb -I../../../include
 LDFLAGS=-L. -lm5
 
 OBJS=m5.o

util/m5/src/Makefile.x86

@@ -28,7 +28,7 @@ CC=gcc
 AS=as
 LD=ld
 
-CFLAGS?=-O2 -DM5OP_ADDR=0xFFFF0000 -I../../include
+CFLAGS?=-O2 -DM5OP_ADDR=0xFFFF0000 -I../../../include
 OBJS=m5.o m5op_x86.o m5_mmap.o
 LUA_HEADER_INCLUDE=$(shell pkg-config --cflags-only-I lua51)
 LUA_OBJS=lua_gem5Op.opic m5op_x86.opic m5_mmap.opic