ASoC: Fix overflow error in routing driver

The reg in soc_dapm_mux is 32-bit. The BE DAI ID passed
as shift(to be operated on the reg) may be more than 31,
which may cause overflow.
Set reg field to SND_SOC_NOPM to avoid any DAPM operation
while passing BE IDs in shift_l field and hence avoid overflow.

Change-Id: Ibbbca04c61b7c56eb4c5a7485a4e93dc28a09709
Signed-off-by: Soumya Managoli <smanag@codeaurora.org>