[ARM] 4581/1: Fix the conditional execution of the NWFPE instructions

Starting with ARMv7-A, conditional execution of undefined instructions
can trigger an exception even if the condition check fails. This patch
modifies the NWFPE support to check the condition before emulating the
instruction.

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