x86_64: simplify cpufreq build

Instead of copying the i386 Makefile and handling path substitutions
just use the i386 cpufreq Makefile.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86_64/kernel/Makefile

@@ -27,7 +27,7 @@ obj-$(CONFIG_KEXEC)		+= machine_kexec.o relocate_kernel.o crash.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_PM)		+= suspend.o
 obj-$(CONFIG_HIBERNATION)	+= suspend_asm.o
-obj-$(CONFIG_CPU_FREQ)		+= cpufreq/
+obj-$(CONFIG_CPU_FREQ)		+= ../../i386/kernel/cpu/cpufreq/
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 obj-$(CONFIG_IOMMU)		+= pci-gart.o aperture.o
 obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary.o tce.o

arch/x86_64/kernel/cpufreq/Makefile

-#
-# Reuse the i386 cpufreq drivers
-#
-
-SRCDIR := ../../../i386/kernel/cpu/cpufreq
-
-obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o
-obj-$(CONFIG_X86_ACPI_CPUFREQ) += acpi-cpufreq.o
-obj-$(CONFIG_X86_SPEEDSTEP_CENTRINO) += speedstep-centrino.o
-obj-$(CONFIG_X86_P4_CLOCKMOD) += p4-clockmod.o
-obj-$(CONFIG_X86_SPEEDSTEP_LIB) += speedstep-lib.o
-
-powernow-k8-objs := ${SRCDIR}/powernow-k8.o
-speedstep-centrino-objs := ${SRCDIR}/speedstep-centrino.o
-acpi-cpufreq-objs := ${SRCDIR}/acpi-cpufreq.o
-p4-clockmod-objs := ${SRCDIR}/p4-clockmod.o
-speedstep-lib-objs := ${SRCDIR}/speedstep-lib.o