Add basic support for the Blackfin architecture

For uClibc, the name of the Blackfin architecture is 'bfin'. Actually,
the naming of the architecture is quite messy: for toolchain tuples
and uClibc, it's bfin, but for the kernel, it's blackfin. We've
arbitraly choosen to name it "blackfin" in Crosstool-NG.

Add Blackfin-related uClibc patch to fix a build failure related to
fork() being used in unistd/daemon.c.

Yann E. MORIN:
Apply the patch to the kernel/linux build script to use 'linux'
in the noMMU tuples. See:
http://sourceware.org/ml/crossgcc/2010-04/msg00010.html

diff -dur strace-4.5.16.orig/net.c strace-4.5.16/net.c

--- strace-4.5.16.orig/net.c	2006-12-13 20:57:23.000000000 +0100

+++ strace-4.5.16/net.c	2007-07-14 19:29:36.000000000 +0200

@@ -800,8 +800,12 @@

 #ifdef SOL_PACKET

 static const struct xlat sockpacketoptions[] = {

+#if defined(PACKET_ADD_MEMBERSHIP)

 	{ PACKET_ADD_MEMBERSHIP,	"PACKET_ADD_MEMBERSHIP"	},

+#endif

+#if defined(PACKET_DROP_MEMBERSHIP)

 	{ PACKET_DROP_MEMBERSHIP,	"PACKET_DROP_MEMBERSHIP"},

+#endif

 #if defined(PACKET_RECV_OUTPUT)

 	{ PACKET_RECV_OUTPUT,		"PACKET_RECV_OUTPUT"	},

 #endif