score: remove deprecated IRQF_DISABLED

This patch removes the use of the IRQF_DISABLED flag
from arch/score/kernel/time.c

It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Lennox Wu <lennox.wu@gmail.com>