dmaengine: ti: k3-udma: Fix BCHAN count with UHC and HC channels

commit 4065fab087a5903f726a62ba7ed13cbcf0543cc2 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git

Unlike other channel counts in CAPx registers, BCDMA BCHAN CNT doesn't
include UHC and HC BC channels. So include them explicitly to arrive at
total BC channel in the instance.

Fixes: 01779473

 ("dmaengine: ti: k3-udma: Initial support for K3 BCDMA")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Jai Luthra <j-luthra@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>