Add the missing symbol to fix build halt on aarch64 targets:
```
Contiguous PTE mappings for user memory (ARM64_CONTPTE) [Y/n/?] (NEW) make[7]: *** [scripts/kconfig/Makefile:85: syncconfig] Error 1
make[6]: *** [Makefile:686: syncconfig] Error 2
```
Signed-off-by: Shiji Yang <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20954
Signed-off-by: Christian Marangi <[email protected]>
# CONFIG_ARM64_AMU_EXTN is not set
# CONFIG_ARM64_BTI is not set
CONFIG_ARM64_CNP=y
+# CONFIG_ARM64_CONTPTE is not set
# CONFIG_ARM64_E0PD is not set
# CONFIG_ARM64_EPAN is not set
# CONFIG_ARM64_ERRATUM_1024718 is not set