brcmfmac: fix nvram processing

The nvram file can hold a key=value combination in which the value
may have spaces, ie. 'RAW1=80 02 fe ff'. The parsing functionality
did not deal with this so it gives an error message:

[621746.311635] brcmfmac: brcmf_nvram_handle_key
	warning: ln=90:col=11: '=' expected, skip invalid key entry

because RAW1=80 is being considerd as key=value pair and it expects
'=' sign after '02' for next key=value pair. This entry can be
completely ignored as firmware does not need it.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@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>