cores/usb: Minor typo fixes

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

cores/usb/doc/mem-map.md

@@ -4,7 +4,7 @@ iCE40 USB Core Memory Map
 Global CSRs
 -----------
 
-### Control / Status (Read / Write addr `0x000`)
+### Control / Status (Read / Write addr `0x00`)
 
 ```
 ,---------------------------------------------------------------,

cores/usb/utils/microcode.py

@@ -150,7 +150,7 @@ mc = [
 		EVT_CLR(EVT_ALL),
 		JEQ('IDLE', 0, EVT_RX_OK),
 
-		# Dispatch do handler
+		# Dispatch to handler
 		LD('pkt_pid'),
 		JEQ('DO_IN', PID_IN),
 		JEQ('DO_OUT', PID_OUT),