bus: brcmstb_gisb: Remove the suppress_bind_attrs attribute of the driver

Even if platform_driver does not set suppress_bind_attrs attribute, when
registering with platform_driver_probe, the value of suppress_bind_attrs is
still true, see __platform_driver_probe().

Signed-off-by: lizhe <sensor1010@163.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>