Add the missing check for platform_get_resource and return error
if it fails.

Fixes: 4b45efe8 ("mfd: Add support for Intel Sunrisepoint LPSS devices")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230609014818.28475-1-jiasheng@iscas.ac.cn