sandbox64: add support for NVMXIP QSPI

enable NVMXIP QSPI for sandbox 64-bit

Adding two NVM XIP QSPI storage devices.

Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/develop/driver-model/nvmxip.rst b/doc/develop/driver-model/nvmxip.rst
index 09afdbc..e85dc22 100644
--- a/doc/develop/driver-model/nvmxip.rst
+++ b/doc/develop/driver-model/nvmxip.rst
@@ -56,7 +56,7 @@
 Supported hardware
 --------------------------------
 
-Any 64-bit plaform.
+Any plaform supporting readq().
 
 Configuration
 ----------------------