libi386/biosacpi.c - bad RSDP checksum search

[Andrew Pantyukhin]

Our boot loader stops searching memory at the first occurrence of
"RSD PTR" while there are BIOSes (e.g. some IBM System x) that
have multiple such strings and the first one does not contain the
correct checksum.

The acpi-ca code does the right thing and continues the search.

Any ACPI experts interested in fixing this? I'll be ready to
test.

Here are some references:
http://www.mail-archive.com/linux-acpi@vger.kernel.org/msg11812.html
http://bugzilla.kernel.org/show_bug.cgi?id=9444