x86: Move qemu CPU fixup function into its own file

This function is specific to qemu so it seems best to keep it separate
from the generic code.

Move it out to a new file and update the condition to use if() instead of
 #ifdef

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
index b6a010e..0e90a38 100644
--- a/arch/x86/cpu/Makefile
+++ b/arch/x86/cpu/Makefile
@@ -54,6 +54,7 @@
 obj-$(CONFIG_INTEL_TANGIER) += tangier/
 obj-$(CONFIG_APIC) += lapic.o ioapic.o
 obj-$(CONFIG_$(SPL_TPL_)X86_32BIT_INIT) += irq.o
+obj-$(CONFIG_QFW) += qfw_cpu.o
 ifndef CONFIG_$(SPL_)X86_64
 obj-$(CONFIG_SMP) += mp_init.o
 endif