brcm47xx: use "firmware" partition name

brcm47xx: use "firmware" partition name

Some time ago, after switching to the mainline bcm47xxpart driver
following patch has been applied:

commit 03cef8725d2062335ffc3de50fc037b294fd458c
Author: hauke <hauke@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date:   Sat Apr 6 22:22:26 2013 +0000

    brcm47xx: use old partition names again for kernel 3.8

    This fixes sysupgrade. The partition names are used all over the Internet in various howtos.

    Thank you russell for spotting this problem.

I propose to revert this change and make sysupgrade use "firmware"
instead. This makes brcm47xx compatible with widely used ar71xx and
after all "firmware" sounds like a much better name for... the firmware.

This change doesn't affect "sysupgrade" usage, because it never takes a
partition name as a parameter. This change only affects users using mtd
tool directly. Hopefully there are not many howtos using "mtd" command.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38973 3c298f89-4303-0410-b956-a3cf2f4a3e73