Snippets for linux 7.1.5 from Alpine ppc64le

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-ppc64le/community/linux-stable/linux-stable-7.1.5-r0.log.

• /home/buildozer/aports/community/linux-stable/src/linux-7.1/drivers/char/nvram.c:56:21: warning: 'nvram_mutex' defined but not used [-Wunused-variable]
     56 | static DEFINE_MUTEX(nvram_mutex);
        |                     ^~~~~~~~~~~