target/adi_v5_swd: fix SWD multidrop

target/adi_v5_swd: fix SWD multidrop

Implementation of ADI v6 introduced banking of DP reg 0.
The accompanying change preventing DP SELECT write before
DP IDR read during connect was added to swd_connect_single() only.
Unchanged swd_connect_multidrop() / swd_multidrop_select_inner()
was broken as it emited DP SELECT and put DP to protocol error state.

Copy dap->select handling to swd_multidrop_select_inner().

Fixes: 72fb88613f02 (adiv6: add low level swd transport)
Change-Id: I514cd6d9ae2ba97ce3657b459df22638c278a0b1
Signed-off-by: Tomas Vanek <vanekt@fbl.cz>
Reviewed-on: https://review.openocd.org/c/openocd/+/7213
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Jonathan Bell <jonathan@raspberrypi.com>