brcmfmac: use consistent function names in dhd_sdio.c

brcmfmac: use consistent function names in dhd_sdio.c

Functions in dhd_sdio.c that are called with struct brcmf_sdio
instance are renamed consistently with brcmf_sdio_ prefix.

Reviewed-by: Franky Lin <[email protected]>
Reviewed-by: Hante Meuleman <[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]>