drivers/net/fm: descend only when CONFIG_FMAN_ENET=y

CONFIG_FMAN_ENET is defined only for CPU mpc85xx.
We do not need to filter by CPU mpc85xx.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>

Makefile

diff --git a/Makefile b/Makefile
index 0e9609f..5cdfc6d 100644
--- a/Makefile
+++ b/Makefile
@@ -271,9 +271,7 @@
 	drivers/power/pmic/libpmic.o \
 	drivers/power/battery/libbattery.o
 LIBS-y += drivers/spi/libspi.o
-ifeq ($(CPU),mpc85xx)
-LIBS-y += drivers/net/fm/libfm.o
-endif
+LIBS-$(CONFIG_FMAN_ENET) += drivers/net/fm/libfm.o
 LIBS-y += drivers/serial/libserial.o
 LIBS-y += drivers/usb/eth/libusb_eth.o
 LIBS-y += drivers/usb/gadget/libusb_gadget.o

drivers/net/fm/Makefile

diff --git a/drivers/net/fm/Makefile b/drivers/net/fm/Makefile
index 2efba76..d0fd7fc 100644
--- a/drivers/net/fm/Makefile
+++ b/drivers/net/fm/Makefile
@@ -4,7 +4,6 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-ifdef CONFIG_FMAN_ENET
 obj-y += dtsec.o
 obj-y += eth.o
 obj-y += fm.o
@@ -33,4 +32,3 @@
 obj-$(CONFIG_PPC_T4160) += t4240.o
 obj-$(CONFIG_PPC_B4420) += b4860.o
 obj-$(CONFIG_PPC_B4860) += b4860.o
-endif