tools/testing/nvdimm: mock ioremap_wt

In the 4.2-rc1 merge the default_memremap_pmem() implementation switched
from ioremap_nocache() to ioremap_wt().  Add it to the list of mocked
routines to restore the ability to run the unit tests.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

tools/testing/nvdimm/Kbuild

@@ -1,3 +1,4 @@
+ldflags-y += --wrap=ioremap_wt
 ldflags-y += --wrap=ioremap_cache
 ldflags-y += --wrap=ioremap_nocache
 ldflags-y += --wrap=iounmap

tools/testing/nvdimm/test/iomap.c

@@ -77,6 +77,12 @@ void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
 }
 EXPORT_SYMBOL(__wrap_ioremap_nocache);
 
+void __iomem *__wrap_ioremap_wt(resource_size_t offset, unsigned long size)
+{
+	return __nfit_test_ioremap(offset, size, ioremap_wt);
+}
+EXPORT_SYMBOL(__wrap_ioremap_wt);
+
 void __wrap_iounmap(volatile void __iomem *addr)
 {
 	struct nfit_test_resource *nfit_res;