We've added two ESR exception classes for new ARM hardware extensions:
ESR_ELx_EC_PAC and ESR_ELx_EC_SVE, but failed to update the strings
used in tracing and other debug.

Let's update "kvm_arm_exception_class" for these two EC, which the
new EC will be visible to user-space via kvm_exit trace events
Also update to "esr_class_str" for ESR_ELx_EC_PAC, by which we can
get more readable debug info.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>