tools/testing/nvdimm: add pfn device dependency

Fail building nfit_test.ko when the configuration is missing pfn device
support.
Reported-by: NMegha Dey <megha.dey@intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

tools/testing/nvdimm/config_check.c

@@ -10,6 +10,7 @@ void check(void)
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_LIBNVDIMM));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_BLK_DEV_PMEM));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_BTT));
+	BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_PFN));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_ND_BLK));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_ACPI_NFIT));
 	BUILD_BUG_ON(!IS_MODULE(CONFIG_DEV_DAX));