staging: brcm80211: remove target platform limitations for drivers

Several issue have been reported building the driver on big endian
systems. Following commits were done on driver Kconfig:

d4620396 Staging: brcm80211: disable drivers except for X86 or MIPS platforms
15e5201d Staging: brcm80211: disable drivers for PPC platforms

These problems have been resolved so the added 'depends' lines in
the Kconfig have been removed.

Compile tested it for following architectures:
little endian
	x86
	x86_64
	arm
	mips
big endian
	ppc64
	sparc64
	mips

Reported-by: David S. Miller <davem@davemloft.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>