tinyalsa: return card number from its name substring

tinyalsa doesn't provide any way to get card number from its name.
Added function to return card number from card name substring. This
is needed as usb audio device can be plug-in and plug-out anytime
which changes card number.

Bug 1009921
Bug 1026047

Change-Id: I2967ede50392e22f2d6f94d0b785209e45cec94f
Reviewed-on: http://git-master/r/163879

(cherry picked from commit 51c575c9e63473f1369f59f3b18d31d3a4abc3dd)

Change-Id: I2967ede50392e22f2d6f94d0b785209e45cec94f
Reviewed-on: http://git-master/r/326330
Tested-by: Jean Huang <jeanh@nvidia.com>
Reviewed-by: Peter Zu <pzu@nvidia.com>
Reviewed-by: Jean Huang <jeanh@nvidia.com>