ArmPkg: Adjust variable type and cast for RegShift & RegOffset

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>
2 files changed