nvmem: remove unneeded IS_ENABLED(CONFIG_NVMEM) conditional

As you see in drivers/nvmem/Makefile, this C file is compiled only
when CONFIG_NVMEM is y or m.

So, IS_ENABLED(CONFIG_NVMEM) is always evaluated to 1 in this file.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/core.c

@@ -615,7 +615,7 @@ static struct nvmem_device *nvmem_find(const char *name)
 	return to_nvmem_device(d);
 }
 
-#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
+#if IS_ENABLED(CONFIG_OF)
 /**
  * of_nvmem_device_get() - Get nvmem device from a given id
  *
@@ -753,7 +753,7 @@ static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id)
 	return cell;
 }
 
-#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
+#if IS_ENABLED(CONFIG_OF)
 /**
  * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
  *