pwm: bcm2835: Fix NPD in suspend/resume

When 119a508c ("pwm: bcm2835: Add support for suspend/resume") was
sent out on October 11th,, there was still a call to
platform_set_drvdata() which would ensure that the driver private data
structure could be used in bcm2835_pwm_{suspend,resume}.

A cleanup now merged as commit commit 2ce7b7f6 ("pwm: bcm2835:
Simplify using devm functions") removed that call which would now cause
a NPD in bcm2835_pwm_{suspend,resume} as a consequence.

Fixes: 119a508c ("pwm: bcm2835: Add support for suspend/resume")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>