ArmPlatformPkg: Renamed and Invoked earlier ArmPlatformNormalInitialize()

ArmPlatformPkg: Renamed and Invoked earlier ArmPlatformNormalInitialize()

- ArmPlatformNormalInitialize() has been renamed into ArmPlatformInitialize()
- Make the function be called at the early stage of the PEI phase as some
  platforms require their interconnects or clocks to be initialize before any
  access to Timers or UARTs.

Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13245 6f19259b-4bc3-4df7-8a09-765794883524