Fix makefiles for hvmloader and vmxassist for FC5 on x86_64

systems.

In FC5, gcc has issues with the command lines used to build
hvmloader and vmxassist.  Basically, the compiler doesn't
like the combination of -m64 and -m32.  As these are 32 bit
apps, and intended to be, take a modified approach and simply
define XEN_TARGET_ARCH for 32 bits.  This cleans up the
command line and builds the images correctly.

From: Ben Thomas <ben@virtualiron.com>

Signed-off-by: Keir Fraser <keir@xensource.com>

tools/firmware/hvmloader/Makefile

@@ -21,6 +21,7 @@
 # External CFLAGS can do more harm than good.
 CFLAGS :=
 
+XEN_TARGET_ARCH = x86_32
 XEN_ROOT = ../../..
 include $(XEN_ROOT)/Config.mk
 
@@ -38,8 +39,7 @@ CFLAGS  += $(call test-gcc-flag,$(CC),-fno-stack-protector)
 CFLAGS  += $(call test-gcc-flag,$(CC),-fno-stack-protector-all)
 
 OBJCOPY  = objcopy
-CFLAGS  += $(DEFINES) -I. $(XENINC) -Wall -fno-builtin -O2 -msoft-float
-CFLAGS  += -m32 -march=i686
+CFLAGS  += $(DEFINES) -I. $(XENINC) -fno-builtin -O2 -msoft-float
 LDFLAGS  = -m32 -nostdlib -Wl,-N -Wl,-Ttext -Wl,$(LOADADDR)
 
 all: hvmloader

tools/firmware/vmxassist/Makefile

@@ -21,6 +21,7 @@
 # External CFLAGS can do more harm than good.
 CFLAGS :=
 
+XEN_TARGET_ARCH = x86_32
 XEN_ROOT = ../../..
 include $(XEN_ROOT)/Config.mk
 
@@ -37,8 +38,7 @@ CFLAGS  += $(call test-gcc-flag,$(CC),-fno-stack-protector-all)
 
 CPP      = cpp -P
 OBJCOPY  = objcopy -p -O binary -R .note -R .comment -R .bss -S --gap-fill=0
-CFLAGS  += $(DEFINES) -I. $(XENINC) -Wall -fno-builtin -O2 -msoft-float
-CFLAGS  += -m32 -march=i686
+CFLAGS  += $(DEFINES) -I. $(XENINC) -fno-builtin -O2 -msoft-float
 LDFLAGS  = -m elf_i386
 
 OBJECTS = head.o trap.o vm86.o setup.o util.o