power_supply: tps65217-charger: fix missing platform_set_drvdata()

Add missing platform_set_drvdata() in tps65217_charger_probe(), otherwise
calling platform_get_drvdata() in remove returns NULL.

This is detected by Coccinelle semantic patch.

Fixes: 3636859b ("power_supply: Add support for tps65217-charger")
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Sebastian Reichel <sre@kernel.org>