ArmPkg/SemihostFs: Implement SetInfo() and handle seeking past the end of a file

ArmPkg/SemihostFs: Implement SetInfo() and handle seeking past the end of a file

Implement the resizing of the file with SetInfo().
Implement the renaming of a file with SetInfo().
Allow to seek past the end of a file.

The support of file resizing implies a rework of the read, write
and close functions. So does the support of seeking past the end
of a file. That why those two changes are done in the same patch.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ronald Cron <ronald.cron@arm.com>
Reviewed-By: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16244 6f19259b-4bc3-4df7-8a09-765794883524