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/syscall.c strace-4.5.16/syscall.c

--- strace-4.5.16.orig/syscall.c	2006-12-21 23:13:33.000000000 +0100

+++ strace-4.5.16/syscall.c	2007-07-14 19:21:44.000000000 +0200

@@ -1045,6 +1045,15 @@

 		/*

 		 * Note: we only deal with only 32-bit CPUs here.

 		 */

+

+		if (!(tcp->flags & TCB_INSYSCALL) &&

+		    (tcp->flags & TCB_WAITEXECVE)) {

+			/* caught a fake syscall from the execve's exit */

+			tcp->flags &= ~TCB_WAITEXECVE;

+			return 0;

+		}

+

+

 		if (regs.ARM_cpsr & 0x20) {

 			/*

 			 * Get the Thumb-mode system call number