Set the coefficient register to 0x1 alone before writing values.

As outlined in the documentation, "start_hlut_coef_write" (or vlut) must be performed before writing the first horizontal (or vertical) resizing coefficient, not in parallel with the write of the first coefficient.
Set the coefficient register to 0x1 alone before writing values.

This commit adds the nearest-neighbor case, forgotten in commit fcc1af2cee3c274740b54e5507fb515dc0076afe.
Add sleeps after the writes to H/V_CONF in the LUT registers.
Merge pull request #4 from Nebuleon/master

Set the coefficient register to 0x1 (H/V_CONF) alone first.