msm: bam_dmux: fix compilation issue

Signed-off-by: Jeffrey Carlyle <jeff.carlyle@motorola.com>
[ljc: also call BUG instead of panic]
Signed-off-by: Luis Cruz <ljc2491@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>