ArmPkg/ProcessorSubClassDxe: Fix the format of ProcessorId
According to SMBIOS 3.4, section 7.5.3.3 ARM64-class CPUs, if
SMCCC_ARCH_SOC_ID is supported, the first DWORD is the JEP-106 code and
the second DWORD is the SoC revision value. But in the current
implementation, they are set in reverse. This patch is to correct it.