arm64: dts: qcom: remove camera_mem region

qcom camera driver allocates the ICP firmware memory
dynamically, so the carveout region is unnecessary.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Link: https://lore.kernel.org/r/20210525133242.188603-1-senozhatsky@chromium.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>