[COMMON] pinctrl: samsung: change FLTCON register setting routine.

[COMMON] pinctrl: samsung: change FLTCON register setting routine.

The FLTCON register offset of each GPIO block is not regular.
To support irregular FLTCON offset of all GPIO block,
we should use fltcon_offset value in driver data to set FLTCON properly.

And we need to check whether both FLTCON0 and FLTCON1 should be set or not.
When nr_pins(The number of pins in the signle GPIO bank)
is greater than 4(The max number of pins in the single GPIO bank),
The FILTCON1 register also should be set.
When nr_pins is not greater than 4, we don't need to set FLTCON1.

Only alive block(gpa) has the filter selection bit.
So we need to set filter selction bit in case of alive block.
If some GPIO block is not alive, we should not set filter selection bit.

Change-Id: Icadc5f8df49fbf9b983918150e7016f96c40e57c
Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Hyunki Koo <hyunki00.koo@samsung.com>