[coreboot] v3 config patch and lar patch

[Myles Watson]

This patch makes PAYLOAD_PREPARSE_ELF only apply to the payload.  It
also separates the lar steps for adding the payload to make this
happen.  Because of that, I also separated the nocompress files so
that there is no need for that style of flag.  I removed it in lar as
well.

I rearranged Kconfig a little so that PAYLOAD_PREPARSE_ELF is an
option if you've selected to have an ELF payload.

I made the Makefile print
    PAYLOAD payload.elf -C lzma
when the payload is compressed and
    PAYLOAD payload.elf
when it isn't.

Myles

Signed-off-by: Myles Watson