dmaengine: qcom_bam_dma: fix wrong register offsets

The commit fb93f520 (dmaengine: qcom_bam_dma: Generalize BAM
register offset calculations) wrongly populated base offsets
for event registers for bam v1.4.

Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Reviewed-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>