adjust gnu arm toolchain directions for newer gcc (7.2.0-14)

Hi all, Just got a new laptop and was trying to build and run fernly (for fernvale/mtk6260) and found that arm-none-eabi toolchain from debian (9ish I think... PureOS is what I am using) doesn't run succesfully. This is a known issue. What really caused me trouble was when I went to use the gnu arm toolchain instructions on the osmocom wiki I ran into problems. My PureOS machine has gcc 7.2.0-14. I wonder if we should add some instructions to the wiki about patches needed and maybe update the shell script to automate these changes if we can isolate them to a particular version of gcc? https://osmocom.org/projects/baseband/wiki/GnuArmToolchain PROBLEM with cfns.gperf fixes FIX: https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=ec1cc0263f156f70693a62cf1… PROBLEM: a few tex problems in gcc docs, @tex should appear at a line beginning FIX: https://gcc.gnu.org/ml/gcc-patches/2013-09/msg02100.html PROBLEM: newlib.../libc/sys/arm/trap.S:88: Error: lo register required -- `sub ip,sp,ip' FIX: https://sourceware.org/ml/newlib/2011/msg00140.html FIX: add --disable-newlib-supplied-syscalls Craig