configs: synquacer: Fix dfu_alt_info to use nor1

Fix dfu_alt_info to use nor1 instead of the device name.
This reverts a part of commit 59bd18d4 ("configs: synquacer:
Remove mtdparts settings and update DFU setting") because the
commit a4f2d834 ("mtd: spi: nor: force mtd name to "nor%d"")
changed the mtd device naming scheme to nor%d.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>