net: ipa: fix canary count for SC7180 UC_INFO region

There should be no canary values written before the beginning of the
UC_INFO memory region.  This was correct for SDM845, but somehow was
committed with the wrong value for SC7180.

This bug seems to cause no harm, so we'll just correct it without
back-porting.

Signed-off-by: Alex Elder <elder@linaro.org>