brcmfmac: Add support for multiple PCIE devices in nvram.

With PCIE it is possible to support multiple devices with the
same device type. They all load the same nvram file. In order to
support this the nvram can specify which part of the nvram is
for which pcie device. This patch adds support for these new
types of nvram files.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>