brcmfmac: remove TRACE level debug message from brcmf_sdio_bus_sleep()

brcmfmac: remove TRACE level debug message from brcmf_sdio_bus_sleep()

The function brcmf_sdio_bus_sleep() function is called rather
frequently, which fills the log when TRACE level is enabled. Reduced
the level to SDIO.

Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>