Change in flashrom[master]: ichspi: Refactor Flashrom HW Sequencing Operation Part I

[Edward O'Callaghan (Code Review)]

Attention is currently required from: Nico Huber, Subrata Banik, Angel Pons, Anastasia Klimchuk.
Edward O'Callaghan has posted comments on this change. ( https://review.coreboot.org/c/flashrom/+/62868 )

Change subject: ichspi: Refactor Flashrom HW Sequencing Operation Part I
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Patch Set 1:

(1 comment)

Commit Message:

https://review.coreboot.org/c/flashrom/+/62868/comment/ba61b0fc_b8e10245 
PS1, Line 9: List of changes:
           : 1. Introduced useful macros (read/write/erase/status etc.) and used
           : throughout the SPI operations.
           : 2. Drop unused macros.
           : 3. SPI operations are using `control register (offset 0x6)` hence
           : converted 32-bit reads into 16-bit read to cover the only hardware
           : sequencing control register alone.
As commented in the pre-review this needs to be split up into multiple patches.

Please take a look over the pre-review comments again.