drm/amd: Fix an out of bounds error in BIOS parser

The array is hardcoded to 8 in atomfirmware.h, but firmware provides
a bigger one sometimes. Deferencing the larger array causes an out
of bounds error.

commit 4fc1ba4a ("drm/amd/display: fix array index out of bound error
in bios parser") fixed some of this, but there are two other cases
not covered by it.  Fix those as well.

Reported-by:  <erhard_f@mailbox.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214853
Link: drm/amd#2473


Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>