ARM: 7770/1: remove residual ARMv2 support from decompressor

arm26 support in Linux is long gone, yet it left an interresting,
fossilized trace in the decompressor.

Remove it so people won't get confused about what teqp is actually
doing here...

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>