[ARM] 4516/1: S3C: Fix uncompressor serial output for ARM926

Ensure we check for ARM926 in the uncompressor, as all current
ARM926s do not have an ID register and all have S3C2440 style
UARTs.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>