msm: camerav2: isp: Reserve rdi ub based on image size

Existing logic will allocate rdi ub with a fixed size,
that will not get enough for 2pd kind of sensors, which
lead overflow, to fix this allocate ub based image size.

Change-Id: I52516ef38fec1bfc1d18d9280c57c8186ccc96e6
Signed-off-by: Ramesh V <ramev@codeaurora.org>