flash/nor, contrib/loaders: move numicro M0 write assembly to contrib/loaders

Simply move numicro M0 flash write assembly to contrib/loaders. Also,
modify corresponding Makefile and generated numicro_m0.inc.

To make the path more general, this patch rename the path
"contrib/loaders/flash/numicro_m4" to "contrib/loaders/flash/numicro" as
well.

Signed-off-by: Jian-Hong Pan <chienhung.pan@gmail.com>
Change-Id: I9adea24c2b3c97319a9b015cf50257f3d131dc26
Reviewed-on: https://review.openocd.org/c/openocd/+/7346
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

contrib/loaders/flash/numicro/Makefile

@@ -0,0 +1,31 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+BIN2C = ../../../../src/helper/bin2char.sh
+
+CROSS_COMPILE ?= arm-none-eabi-
+
+CC=$(CROSS_COMPILE)gcc
+OBJCOPY=$(CROSS_COMPILE)objcopy
+OBJDUMP=$(CROSS_COMPILE)objdump
+
+
+AFLAGS = -static -nostartfiles -mlittle-endian -Wa,-EL
+
+all: numicro_m0.inc numicro_m4.inc
+
+.PHONY: clean
+
+%.elf: %.S
+	$(CC) $(AFLAGS) $< -o $@
+
+%.lst: %.elf
+	$(OBJDUMP) -S $< > $@
+
+%.bin: %.elf
+	$(OBJCOPY) -Obinary $< $@
+
+%.inc: %.bin
+	$(BIN2C) < $< > $@
+
+clean:
+	-rm -f *.elf *.lst *.bin *.inc