mfd: t7l66xb: Remove unnecessary pdata check

 o Making pdata NULL check to (!pdata) as coding standard
	and all other checks in file.
 o Removing redundant check of pdata, because we already
	check for pdata, and also derefernced before this check.

Signed-off-by: Maninder Singh <maninder1.s@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>