diag: dci: Send mode reset command to the apps processor

Diag driver was sending all mode commands to the apps processor while
only mode reset command was handled on the apps processor. This patch
makes an exception for mode reset command.

Change-Id: I51e4971cbffcc8fedd68090cb5a15c4c67363c57
Signed-off-by: Ravi Aravamudhan <aravamud@codeaurora.org>