P4080/eLBC: Make Freescale elbc interrupt common to elbc devices

Move Freescale elbc interrupt from nand driver to elbc driver.
Then all elbc devices can use the interrupt instead of ONLY nand.

For former nand driver, it had the two functions:

1. detecting nand flash partitions;
2. registering elbc interrupt.

Now, second function is removed to fsl_lbc.c.

Signed-off-by: Lan Chunhe-B25806 <b25806@freescale.com>
Signed-off-by: Roy Zang <tie-fei.zang@freescale.com>
Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Wood Scott-B07421 <B07421@freescale.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>