Use nrfxlib-sys 1.5.1-rc1

Author: Jonathan Pallant (42 Technology)

Cargo.toml

@@ -15,6 +15,4 @@ cortex-m = "0.6"
 heapless = "0.7"
 linked_list_allocator = { version="0.9.0", default-features=false, features=["use_spin"] }
 log = "0.4"
-# nrfxlib-sys = "1.5.1"
-nrfxlib-sys = { git = "https://github.com/42-technology-ltd/nrfxlib-sys.git", branch = "update_to_1.5.1" }
-# nrfxlib-sys = { path = "../nrfxlib-sys" }
+nrfxlib-sys = "1.5.1-rc1"