wcnss: Sample WCNSS TOP AHB clock on WCNSS WDOG bite

Sample the wcss_top_ahb_clk and determine whether or not the clock freq
is zero when the issue occurs. This will help confirm the reason for
the system reset when Apps tries to access PMU registers for logging
purposes.

Change-Id: Ia4f34a38b7e8d237b9e5ae935d9ce339ca2d6ed1
Signed-off-by: Yue Ma <yuem@codeaurora.org>