[coreboot] src/soc/intel/xeon_sp/Kconfig:95:warning: config symbol defined without type

[Mike Banon]

After this commit - https://review.coreboot.org/c/coreboot/+/79058 -
now I always have this warning while doing a "make menuconfig" :

src/soc/intel/xeon_sp/Kconfig:95:warning: config symbol defined without type

To fix this, please add the "bool" line before "default y" to specify
the config symbol type.

P.S. wrote about this problem under the change about ~1 month ago, but
maybe the notifications are not working for the merged changes - so
posting it here just in case