target hardfp by default.

L4 is an M4F, so use hardfp ABI by default.
Drop irrelevant targets completely, but leave the commented out option
for people who really insist on using softfp.

Signed-off-by: Karl Palsson <karlp@etactica.com>

Author: karlp

.cargo/config

@@ -27,7 +27,5 @@ rustflags = [
 
 [build]
 # Pick ONE of these compilation targets
-# target = "thumbv6m-none-eabi"    # Cortex-M0 and Cortex-M0+
-# target = "thumbv7m-none-eabi"    # Cortex-M3
-target = "thumbv7em-none-eabi"   # Cortex-M4 and Cortex-M7 (no FPU)
-# target = "thumbv7em-none-eabihf" # Cortex-M4F and Cortex-M7F (with FPU)
+# target = "thumbv7em-none-eabi"   # Cortex-M4 and Cortex-M7 (no FPU)
+target = "thumbv7em-none-eabihf" # Cortex-M4F and Cortex-M7F (with FPU)