mtd: brcmnand: refactor bcm63138 SoC layering
mtd: brcmnand: refactor bcm63138 SoC layering

Removes an unnecessary allocation and saves a little bit of pointer
chasing.

Signed-off-by: Brian Norris <ac73eed4b8a8c9127255a2696c52b2e7503720b8@gmail.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs