spi: sprd: Fix the wrong WDG_LOAD_VAL

Use 50ms as default timeout value and the time clock is 32768HZ.
The original value of WDG_LOAD_VAL is not correct, so this patch
fixes it.

Fixes: ac177501 ("spi: sprd: Add the support of restarting the system")
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20210826091549.2138125-2-zhang.lyra@gmail.com


Signed-off-by: Mark Brown <broonie@kernel.org>