ASoC: core: Remove sound card state check from read/write

Having sound card offline condition checks inside
register read/write functions will also avoid Asoc
cache writes. However, it is needed to update the
Asoc cache whenever user-space sends disable sequence
while sound card is in offline state. Remove the offline
check condition from ASoC read/writes and let the codec
driver take care of not sending bus read/writes if sound
card is in offline state.

Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>
Change-Id: I960b85a277a28dd05eb919c1c6abf7aa32a45265