add support for gr740 and generic flash driver

[lukileczo]

Description

• adapt grlib-multi to gr740 target
• implement generic flash driver for GRLIB based targets (GR712RC, GR740, NOEL-V)

Motivation and Context

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Chore (refactoring, style fixes, git/CI config, submodule management, no code logic changes)

How Has This Been Tested?

• Already covered by automatic testing.
• New test added: (add PR link here).
• Tested by hand on: (list targets here).

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing linter checks and tests passed.
• My changes generate no new compilation warnings for any of the targets.

Special treatment

• This PR needs additional PRs to work (list the PRs, preferably in merge-order).
• add support for gr740 phoenix-rtos-tests#389
• sparcv8leon: implement port for GR740 CPU phoenix-rtos-kernel#632
• add support for gr740, update sparc targets configuration phoenix-rtos-project#1260
• arch/sparcv8leon: add support for GR740 CPU libphoenix#401
• _targets: add sparcv8leon-gr740 phoenix-rtos-filesystems#143
• _targets: add sparcv8leon-gr740 phoenix-rtos-utils#230
• add support for gr740 plo#375
• add support for gr740 and generic flash driver #532
• add sparcv8leon-gr740 target phoenix-rtos-build#222
• _targets: add sparcv8leon-gr740 phoenix-rtos-filesystems#143
• I will merge this PR by myself when appropriate.

[agkaminski]

Some nitpicks. For the future - it should be possible to share even more code between the drivers, especially driver init/deinit share quite a lot of common parts