upgrade nrfx from 2.0.0 to 2.1.0

hw/mcu/nordic/nrfx

@@ -1 +1 @@
-Subproject commit 7a4c9d946cf1801771fc180acdbf7b878f270093
+Subproject commit 281cc2e178fd9a470d844b3afdea9eb322a0b0e8