Build: remove comment about DOWNLOAD variable

Signed-off-by: Huaqi Fang <[email protected]>

Build/Makefile.base

@@ -20,7 +20,6 @@ endif
 SOC ?= evalsoc
 ## Available choices:
 ## ilm: Program will be download into ilm/ram and run directly in ilm/ram, program lost when poweroff
-## flash: Program will be download into flash, when running, program will be copied to ilm/ram and run in ilm/ram
 ## flashxip: Program will to be download into flash and run directly in Flash
 DOWNLOAD ?= ilm
 ## If SIMULATION=1, it means the program is optimized for hardware simulation environment