imx: spl: enable CONFIG_SPL_WATCHDOG_SUPPORT

imx: spl: enable CONFIG_SPL_WATCHDOG_SUPPORT

This commit 4bdcbe60a142b08eefccb0e326a37ba81d3389e8 removes reset_cpu
which breaks SPL build when DEBUG macro defined.

"
arch/arm/lib/built-in.o: In function `do_reset':
~/uboot/arch/arm/lib/reset.c:45: undefined reference to `reset_cpu'
scripts/Makefile.spl:244: recipe for target 'spl/u-boot-spl' failed
"
Enable CONFIG_SPL_WATCHDOG_SUPPORT to fix this issue.

Signed-off-by: Peng Fan <[email protected]>
Cc: Stefano Babic <[email protected]>
Cc: Fabio Estevam <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: Tim Harvey <[email protected]>
Acked-by: Eric Nelson <[email protected]>