ASoC: simple-card: Fix misleading error message

commit 7ac45d1635a4cd2e99a4b11903d4a2815ca1b27b upstream.

In case cpu could not be found the error message would always refer to
/codec/ not being found in DT. Fix this by catching the cpu node not found
case explicitly.

Signed-off-by: Julian Scheel <julian@jusst.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: thongsyho <thong.ho.px@rvc.renesas.com>
Signed-off-by: Nhan Nguyen <nhan.nguyen.yb@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>