mfd: smsc-ece1099: Remove unnecessarily remove callback

SMSC MFD driver does not add any MFD child devices via
mfd_add_devices() and hence it is not required to call
mfd_remove_devices() to remove MFD child devices.

Remove the call of the API mfd_remove_devices() which will
result as remove of .remove callback for driver.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>