Do not warn if start of section is changed

Remove ld option 'warn-section-align', as by default, SECTIONS command
does not specify a start address for the section, let ld do the work.
If a start address is specified no warn was displayed.

--warn-section-align
    Warn if the address of an output section is changed because of
    alignment. Typically, the alignment will be set by an input section.
    The address will only be changed if it not explicitly specified;
    that is, if the SECTIONS command does not specify a start address
    for the section.

Fix #465

Signed-off-by: Frederic.Pillon <[email protected]>

Author: fpistm

platform.txt

@@ -37,7 +37,7 @@ compiler.cpp.flags={compiler.extra_flags} -c {build.flags.optimize} {compiler.wa
 
 compiler.ar.flags=rcs
 
-compiler.c.elf.flags=-mcpu={build.mcu} -mthumb {build.flags.optimize} {build.flags.ldspecs} -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--entry=Reset_Handler -Wl,--unresolved-symbols=report-all -Wl,--warn-common -Wl,--warn-section-align
+compiler.c.elf.flags=-mcpu={build.mcu} -mthumb {build.flags.optimize} {build.flags.ldspecs} -Wl,--cref -Wl,--check-sections -Wl,--gc-sections -Wl,--entry=Reset_Handler -Wl,--unresolved-symbols=report-all -Wl,--warn-common
 
 compiler.objcopy.eep.flags=-O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0