msm: vidc: ARM: dts: msm: fix non secure CB size

Non secure context bank size should be 1784 MB
instead of 2160 MB, hence correct the same.

Change-Id: I133d427d2f6109bb6e5c133240438925ddf6555e
Signed-off-by: Mahesh Voorugonda <mvooru@codeaurora.org>