brcmfmac: remove duplication of ramsize info

Removing the ramsize from the brcmf_sdio structure to avoid
duplication. The information is available in brcmf_chip
structure.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>