[coreboot] Coreinfo build patch

[Myles Watson]

Change the default path to libpayload since they are both in payloads/.
Change LAR support to default to no, since that is the default in libpayload.

With this change, the steps to build coreinfo are:

1. Build libpayload:
cd payloads/libpayload
make menuconfig
make install

2. Build coreinfo
cd ../coreinfo
make menuconfig
make

Signed-off-by: Myles Watson

Thanks,
Myles