msm: camera: core: Fix cpas axi clk rate overflow

Change the clk variable type from int32_t to int64_t
to avoid integer overflow.

CRs-Fixed: 2609090
Change-Id: I9f785ce2c1e45b1e9a238c42e86da1161bf70f75
Signed-off-by: Ravikishore Pampana <rpampana@codeaurora.org>