ARM: 7275/1: LPAE: Check the CPU support for the long descriptor format

This patch adds a check for the presence of the LPAE feature during the
CPU initialisation. If not present, it reports an error when
CONFIG_DEBUG_LL is enabled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>