unify build/defconfig and modify/defconfig

they fundamentally perform the same action: copy
the .config file and run make, but build runs
make-all, while modify runs make-oldconfig or
make-menuconfig

merge this functionality together

also:
./handle config file

^ this is the new syntax, not:
./build defconfig for

for example:

./handle config file -b coreboot x200_8mb <-- build x200 rom
./handle config file -m coreboot x200_8mb <-- modify configs
./handle config file -u coreboot x200_8mb <-- make-oldconfig
./handle config file -u seabios
./handle config file -b u-boot

yes, 1 script and a sloccount reduction of 52. and the audit?
it continues.

Signed-off-by: Leah Rowe <leah@libreboot.org>

resources/scripts/build/boot/roms_helper

@@ -166,7 +166,7 @@ if [ ! -f "${seavgabiosrom}" ] \
     || [ ! -f elf/seabios/default/vgarom/bios.bin.elf ] \
     || [ ! -f elf/seabios/default/normal/bios.bin.elf ]; then
 	[ "${payload_seabios}" = "y" ] && \
-		./build defconfig for seabios
+		./handle config file -b seabios
 fi
 
 [ "${payload_memtest}" = "y" ] && [ ! -f "memtest86plus/memtest" ] && \
@@ -211,7 +211,7 @@ if [ "${payload_grub}" = "y" ] \
 fi
 
 if [ "${payload_uboot}" = "y" ]; then
-	./build defconfig for u-boot ${board}
+	./handle config file -b u-boot ${board}
 	ubdir="elf/u-boot/${board}/${uboot_config}"
 	ubootelf="${ubdir}/u-boot.elf"
 	[ ! -f "${ubootelf}" ] && [ -f "${ubdir}/u-boot.bin" ] && \
@@ -497,7 +497,8 @@ mkRoms()
 		return 0
 	fi
 
-	./build defconfig for coreboot ${board}
+	./handle config file -b coreboot ${board}
+
 	_corebootrom="elf/coreboot/${board}/${initmode}_${displaymode}"
 	[ "${initmode}" = "normal" ] && \
 		_corebootrom="${_corebootrom%_${displaymode}}"