ARM: 7711/1: dove: fix Dove cpu type from V7 to PJ4

The CPU used in Marvell Dove SoCs is a PJ4 Sheeva core. Using
CONFIG_CPU_PJ4 instead of CONFIG_CPU_V7 will enable iWMMXt
extensions on Dove.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>