asoc: sm6150: Correct codec_root entry creation logic

Create codec root entry only if it is not
created already in proc directory to avoid failures
in codec version entry enumeration.

Change-Id: I8c912be5fb0f229a3b5a088ebb5c0aeea06f67b2
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>