vela: Rename --keep-scale-placement CLI

 - Changed to --cache-bias-scale-tensor

Signed-off-by: Tim Hall <tim.hall@arm.com>
Change-Id: I285fe253f03ba98eff36dbe996ad3a57e2ee3d99
diff --git a/ethosu/vela/compiler_driver.py b/ethosu/vela/compiler_driver.py
index 7b1ea21..d17f1e5 100644
--- a/ethosu/vela/compiler_driver.py
+++ b/ethosu/vela/compiler_driver.py
@@ -174,7 +174,7 @@
     # block config, and calc and pack the scales and biases
     weight_compressor.update_pass_weight_and_scale_tensors(nng, arch)
 
-    if not scheduler_options.keep_scale_placement:
+    if scheduler_options.cache_bias_scale_tensor:
         scheduler.move_scales_to_fast_storage(nng, arch)
 
     # LiveRanges for constant tensors for all Npu subgraphs