Platform/NXP/LS1046aFrwyPkg: Fix build break due to change in ARM_CORE_INFO

The edk2 patch at 103fa647d159e3d76be2634d2653c2d215dd0d46
updated the ARM_CORE_INFO structure to remove the ClusterId
and CoreId fields in the ARM_CORE_INFO structure in favor of
a new Mpidr field.

Therefore, fix the ArmPlatformLibrary instance for
Platform/NXP/LS1046aFrwyPkg accordingly.

Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>