onenand: Replace ONENAND_IS_MLC() with ONENAND_HAS_4KB()

onenand: Replace ONENAND_IS_MLC() with ONENAND_HAS_4KB()

This replacement causes 4KB page size devices to work properly with u-boot.

The old ONENAND_IS_MLC() behavior has been preserved by explicit
setting of ONENAND_HAS_4KB_PAGE for those devices.

This change makes the onenand_base.c file more resembling the respective
kernel sources.

Signed-off-by: Lukasz Majewski <[email protected]>
Signed-off-by: Kyungmin Park <[email protected]>
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Test HW:
       - Samsung S5PC110 GONI
       - Samsung S5PC210 Universal