[PATCH] matroxfb: read MGA PInS data on PowerPC

This updates the matroxfb code so that it can find the PInS data embedded
in the BIOS on PowerPC cards.  The process for finding the data is
different on OpenFirmware cards than on x86 cards, and the code for doing
so was missing.

After patching, building, installing, and booting a kernel, you should grep
for "PInS" in /var/log/messages.  You should see two messages in the log:

PInS data found at offset XXXXX
PInS memtype = X

On the GXT135p card I get "31168" and "5".  The first value is irrelevant,
but it's presence lets me know that the PInS data was actually found.  On a
GXT130p, the second value should be 3.  Since I don't have access to that
hardware, if someone can verify that, I will submit a follow-on patch that
rips out all the memtype parameter stuff.

Signed-off-by: Ian Romanick <idr@us.ibm.com>
Signed-off-by: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>