toolchain: drop codescape mips toolchains

toolchain: drop codescape mips toolchains

Codescape mips toolchains are old (2018) and use glibc 2.20 which is not
compatible with 64-bit time_t raising the following build failure with
libselinux since commit 1c2dbcdcf0bb589d325c379246acaa39bb07b7be:

In file included from selinux_restorecon.c:17:0:
/home/buildroot/autobuild/instance-1/output-1/host/mipsel-buildroot-linux-gnu/sysroot/usr/include/fts.h:41:3: error: #error "<fts.h> cannot be used with -D_FILE_OFFSET_BITS==64"
 # error "<fts.h> cannot be used with -D_FILE_OFFSET_BITS==64"
   ^~~~~

Fixes: 1c2dbcdcf0bb589d325c379246acaa39bb07b7be
 - http://autobuild.buildroot.org/results/a4d38af627a42a2c55d60129787c51353d5883bf

Signed-off-by: Fabrice Fontaine <[email protected]>
Signed-off-by: Arnout Vandecappelle <[email protected]>