x86: edison: Avoid passing FORCE to the align command

Commit bd3f9ee679 ("kbuild: Bump the build system to 6.1") adds FORCE
as a prerequisite to the u-boot-align.bin rule, but cmd_mkalign_eds
expands $^, so FORCE leaks in as a stray operand. The dd then fails
(silently, since its stderr is discarded) and the following mv never
runs, so u-boot.bin never gains its 4096-byte zero prefix. The mask ROM
enters U-Boot 0x1000 (4KB) into the image and the board never starts,
sitting in BootROM download mode (DnX).

Use $< instead of $^, which excludes FORCE and restores the prefix.

Fixes: bd3f9ee679 ("kbuild: Bump the build system to 6.1")
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

board/intel/edison/config.mk

@@ -7,8 +7,8 @@
 # Add 4096 bytes of zeroes to u-boot.bin
 quiet_cmd_mkalign_eds = EDSALGN $@
 cmd_mkalign_eds =							\
-	dd if=$^ of=$@ bs=4k seek=1 2>/dev/null &&			\
-	mv $@ $^
+	dd if=$< of=$@ bs=4k seek=1 2>/dev/null &&			\
+	mv $@ $<
 
 INPUTS-y += u-boot-align.bin
 u-boot-align.bin: u-boot.bin FORCE