wifi: ath6kl: sdio: simplify module initialization

This driver's initialization functions do not perform any custom code,
except printing messages.  Printing messages on modules
loading/unloading is discouraged because it pollutes the dmesg
regardless whether user actually has this device.  Core kernel code
already gives tools to investigate whether module was loaded or not.

Drop the printing messages which allows to replace open-coded
module_sdio_driver().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240329171019.63836-2-krzysztof.kozlowski@linaro.org