Makefile: Remove -nostartfiles from LDFLAGS

Binutils linker ld does not support the flag -nostartfiles.
This is interpreted as "-n -o startfiles" which fortunately has no impact
on the build process. Removing -nostartfiles has no impact on the build.

Binutils 2.36 and later ld has improved flag parsing and throws an error if
-nostartfiles is passed as an argument. Removing the flag fixes the problem.

Details on the Binutils ML:
https://sourceware.org/pipermail/binutils/2021-June/116826.html

In our ld command line there are explicit
-n -o $(BINDIR)/$(BOOT_NAME).elf options,
hence removing -nostartfiles will not alter the build.

Signed-off-by: Chris Elledge <celledge@digitallumensinc.com>
Reviwed-by: Aubin Constans <aubin.constans@microchip.com>

Makefile

@@ -283,7 +283,7 @@ endif
 #    --cref:    add cross reference to map file
 #  -lc 	   : 	tells the linker to tie in newlib
 #  -lgcc   : 	tells the linker to tie in newlib
-LDFLAGS=-nostartfiles -Map=$(BINDIR)/$(BOOT_NAME).map --cref -static
+LDFLAGS=-Map=$(BINDIR)/$(BOOT_NAME).map --cref -static
 LDFLAGS+=-T $(link_script) $(GC_SECTIONS) -Ttext $(LINK_ADDR)
 
 ifneq ($(DATA_SECTION_ADDR),)