tree/: Convert unlock func ptr into enumerate values

By converting the blockprotect unlock function pointer
within the flashchip struct into enum values allows for
the flashchips db to be turn into pure, declarative data.
A nice side-effect of this is to reduce link-time symbol
space of chipdrivers and increase modularity of the
spi25_statusreg.c and related implementations.

BUG=none
TEST=ninja test.

Change-Id: Ie5c5db1b09d07e1a549990d6f5a622fae4c83233
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
---
M 82802ab.c
M flashrom.c
M include/chipdrivers.h
M include/flash.h
M jedec.c
M spi25_statusreg.c
M tests/chip.c
M tests/chip_wp.c
8 files changed, 151 insertions(+), 73 deletions(-)