[coreboot] improved GETPIR tool

[mbertens]

Signed-off-by: Marc Bertens

Hi all,

I improved the getpir tool. The following addidion is mode.

- getpir accepts one commandline argument as the memory file (like
coreboot_ram, in the build direcory) it checks the PIRQ table and dumps
the PIRQ table to the stdout. Without parameters it behaves like
before.

This is very handy when configuring a static PRIQ table in the mainboard
code.

Marc