soc: qcom: Add broadcast base for Last Level Cache Controller (LLCC)

Currently, broadcast base is set to end of the LLCC banks, which may
not be correct always. As the number of banks may vary for each chipset
and the broadcast base could be at a different address as well. This info
depends on the chipset, so get the broadcast base info from the device
tree (DT). Add broadcast base in LLCC driver and use this for broadcast
writes.

Signed-off-by: Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>
Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>