[MLBEDSW-4623] Fix sub-module imports

Fixed sub-module imports.

Signed-off-by: Fredrik Svedberg <fredrik.svedberg@arm.com>
Change-Id: I6ab5c04ba5f3411f8cf8ac95606fe036fae11442
diff --git a/ethosu/vela/ethos_u55_regs/__init__.py b/ethosu/vela/ethos_u55_regs/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/ethosu/vela/ethos_u55_regs/__init__.py
diff --git a/setup.py b/setup.py
index 18c0bc7..81a6c00 100644
--- a/setup.py
+++ b/setup.py
@@ -82,7 +82,7 @@
         "Topic :: Software Development :: Compilers",
     ],
     keywords=["ethos-u", "vela compiler", "tflite", "npu"],
-    packages=["ethosu.vela", "ethosu.mlw_codec"],
+    packages=["ethosu.vela", "ethosu.vela.ethos_u55_regs", "ethosu.vela.tflite", "ethosu.mlw_codec"],
     python_requires="~=3.6",  # We support only 3.6+
     install_requires=[
         "flatbuffers==1.12.0",