TOSA: Decompose elem op tensors

Added decomposition of tensors exceeding
maximum size supported by NPU.

Signed-off-by: Patrik Gustavsson <patrik.gustavsson@arm.com>
Change-Id: I17a99cb72947d2f1064a631ad6975ce895c258d5
diff --git a/ethosu/vela/shape4d.py b/ethosu/vela/shape4d.py
index 08b2a6a..fd1ee94 100644
--- a/ethosu/vela/shape4d.py
+++ b/ethosu/vela/shape4d.py
@@ -111,6 +111,9 @@
     def __sub__(self, rhs):
         return Shape4D(self.batch - rhs.batch, self.height - rhs.height, self.width - rhs.width, self.depth - rhs.depth)
 
+    def floordiv_const(self, const):
+        return Shape4D(self.batch // const, self.height // const, self.width // const, self.depth // const)
+
     def __floordiv__(self, rhs):
         return Shape4D(
             self.batch // rhs.batch, self.height // rhs.height, self.width // rhs.width, self.depth // rhs.depth