defconfig: enable memlat governor for qcs403-lc target

Enable memlatancy governor to scale the device frequency
if the executed load is memory latency bound for qcs403-lc
target.

Change-Id: I8a888883187bfc563443181516737adc1129f0d3
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>