arch: disable nios2
The nios2 architecture was deprecated in gcc-14 and has been removed
in the upcoming gcc-15 [1][2].
Our last and only nios2 defconfig "qemu_nios2_10m50_defconfig" was
removed in 2024.11 due to nios2 removal from Qemu 9.1.0 [3].
This patch only definitively hides the symbol. When all references
to it are removed (to come in followup patches), we'll eventually
remove the symbol altogether.
[1] https://sourceware.org/pipermail/binutils/2024-April/133675.html
[2] https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=e876acab6cdd84bb2b32c98fc69fb0ba29c81153
[3] f96b4c176f6e9d6c4374a0d322de672bf44c35bf
Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Julien Olivain <ju.o@free.fr>
Romain Naour