x86: Rename pcat_ to i8254 and i8259 accordingly

Rename pcat_timer.c to i8254.c and pcat_interrupts.c to i8259.c,
to match their header file names (i8254.h and i8259.h).

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 2f82a21..d676e2c 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -19,8 +19,8 @@
 obj-y	+= mpspec.o
 obj-$(CONFIG_ENABLE_MRC_CACHE) += mrccache.o
 obj-y += cmd_mtrr.o
-obj-$(CONFIG_SYS_PCAT_INTERRUPTS) += pcat_interrupts.o
-obj-$(CONFIG_SYS_PCAT_TIMER) += pcat_timer.o
+obj-$(CONFIG_I8259_PIC) += i8259.o
+obj-$(CONFIG_I8254_TIMER) += i8254.o
 ifndef CONFIG_DM_PCI
 obj-$(CONFIG_PCI) += pci_type1.o
 endif