According to the GIC architecture version 3 and 4 specification, the maximum number of INTID bits supported in the CPU interface is 24. Considering this the RegShift variable is not required to be more than 8 bits. Therefore, make the RegShift variable type to UINT8. Also add necessary typecasts when calculating the RegOffset and RegShift values. Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>