Fix left shift overflow issue when the parameter idx is greater than or
equal to 8 in the calculation of perm in PIRx_ELx_PERM macro.

Fix this by modifying the encoding to use a long integer type.
Signed-off-by: Shiqi Liu <shiqiliu@hust.edu.cn>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20240421063328.29710-1-shiqiliu@hust.edu.cnSigned-off-by: Will Deacon <will@kernel.org>