brcmfmac: assure active clock request upon entering SLEEP state

brcmfmac: assure active clock request upon entering SLEEP state

When the SDIO driver goes in low power state it must assure that
a clock request in ChipCLKCSR is set. Otherwise waking up the
device can fail. The register is read and if necessary the ALP
clock will be requested.

Reviewed-by: Daniel (Deognyoun) Kim <[email protected]>
Reviewed-by: Hante Meuleman <[email protected]>
Reviewed-by: Franky (Zhenhui) Lin <[email protected]>
Reviewed-by: Pieter-Paul Giesberts <[email protected]>
Signed-off-by: Arend van Spriel <[email protected]>
Signed-off-by: John W. Linville <[email protected]>