linux-guf: Remove STACKPROTECTOR_PER_TASK

Remove CONFIG_STACKPROTECTOR_PER_TASK defconfig as it breaks the build.

With this enabled and with the jump from Linux 5.10.57 to 5.10.104 I see
the following error:
```
  HOSTCXX scripts/gcc-plugins/arm_ssp_per_task_plugin.so
In file included from ../5.10.57-r0/recipe-sysroot-native/usr/bin/arm-guf-linux-gnueabi/../../lib/arm-guf-linux-gnueabi/gcc/arm-guf-linux-gnueabi/9.3.0/plugin/include/gcc-plugin.h:29,
                 from ../linux-guf/scripts/gcc-plugins/gcc-common.h:7,
                 from ../linux-guf/scripts/gcc-plugins/arm_ssp_per_task_plugin.c:3:
../linux-guf/5.10.57-r0/recipe-sysroot-native/usr/bin/arm-guf-linux-gnueabi/../../lib/arm-guf-linux-gnueabi/gcc/arm-guf-linux-gnueabi/9.3.0/plugin/include/coretypes.h:430:10: fatal error: poly-int.h: No such file or directory
  430 | #include "poly-int.h"
      |          ^~~~~~~~~~~~
compilation terminated.

Seems to be similar to https://lists.yoctoproject.org/g/poky/message/12619

Form my point of view this is a missing header inside the gcc-plugin
package, and should be fixed there. However, right now we just remove
the feature from the kernel.

recipes-kernel/linux/linux-guf-5.10/imx6guf/defconfig

@@ -32,6 +32,7 @@ CONFIG_SMP=y
 CONFIG_ARM_PSCI=y
 CONFIG_HIGHMEM=y
 CONFIG_FORCE_MAX_ZONEORDER=14
+# CONFIG_STACKPROTECTOR_PER_TASK is not set
 CONFIG_ZBOOT_ROM_TEXT=0
 CONFIG_ZBOOT_ROM_BSS=0
 CONFIG_ARM_APPENDED_DTB=y

recipes-kernel/linux/linux-guf-5.10/imx6ullguf/defconfig

@@ -24,6 +24,7 @@ CONFIG_HAVE_ARM_ARCH_TIMER=y
 CONFIG_ARM_PSCI=y
 CONFIG_HIGHMEM=y
 CONFIG_FORCE_MAX_ZONEORDER=14
+# CONFIG_STACKPROTECTOR_PER_TASK is not set
 CONFIG_ZBOOT_ROM_TEXT=0
 CONFIG_ZBOOT_ROM_BSS=0
 CONFIG_ARM_APPENDED_DTB=y