Revert "chore: disable warning about rwx segments"

This reverts commit 794945c.

Author: fpistm

platform.txt

@@ -79,7 +79,7 @@ compiler.objcopy.eep.flags=-O ihex -j .eeprom --set-section-flags=.eeprom=alloc,
 compiler.elf2bin.flags=-O binary
 compiler.elf2hex.flags=-O ihex
 
-compiler.ldflags=-Wl,--no-warn-rwx-segments
+compiler.ldflags=
 compiler.size.cmd=arm-none-eabi-size
 compiler.define=-DARDUINO=