examples: Remove duplicate example linker scripts.

Only add one linker script per eval board, and have the Makefiles use that.

This avoids duplication, and various copy-paste errors and left-overs
which we already have in the tree.

Some of the linker scripts are not really correct, yet. Both, the comments
which say which board, chip, and RAM/ROM sizes are used, as well as the
actual RAM/ROM size definitions are sometimes copy-pasted from other boards
and are thus incorrect. This needs to be fixed.

examples/stm32/f1/Makefile.include

@@ -30,7 +30,7 @@ GDB		= $(PREFIX)-gdb
 TOOLCHAIN_DIR   = ../../../../..
 CFLAGS		+= -Os -g -Wall -Wextra -I$(TOOLCHAIN_DIR)/include \
 		   -fno-common -mcpu=cortex-m3 -mthumb -msoft-float -MD -DSTM32F1
-LDSCRIPT	= $(BINARY).ld
+LDSCRIPT	?= $(BINARY).ld
 LDFLAGS		+= -lc -lnosys -L$(TOOLCHAIN_DIR)/lib -L$(TOOLCHAIN_DIR)/lib/stm32/f1 \
 		   -T$(LDSCRIPT) -nostartfiles -Wl,--gc-sections \
 		   -mthumb -march=armv7 -mfix-cortex-m3-ldrd -msoft-float