efi_selftest: SNP test depends on network

If CONFIG_NET=n, testing the simple network protocol makes no sense.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_selftest/Makefile b/lib/efi_selftest/Makefile
index e9baa64..7f84903 100644
--- a/lib/efi_selftest/Makefile
+++ b/lib/efi_selftest/Makefile
@@ -32,7 +32,6 @@
 efi_selftest_open_protocol.o \
 efi_selftest_register_notify.o \
 efi_selftest_set_virtual_address_map.o \
-efi_selftest_snp.o \
 efi_selftest_textinput.o \
 efi_selftest_textinputex.o \
 efi_selftest_textoutput.o \
@@ -42,6 +41,8 @@
 efi_selftest_variables_runtime.o \
 efi_selftest_watchdog.o
 
+obj-$(CONFIG_NET) += efi_selftest_snp.o
+
 obj-$(CONFIG_EFI_DEVICE_PATH_TO_TEXT) += efi_selftest_devicepath.o
 obj-$(CONFIG_EFI_UNICODE_COLLATION_PROTOCOL2) += \
 efi_selftest_unicode_collation.o