clocksource: davinci: axe a pointless __GFP_NOFAIL

There is no need to specify __GFP_NOFAIL when allocating memory here, so
axe it.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200409101226.15432-1-christophe.jaillet@wanadoo.fr