perf/smmuv3: Add MODULE_ALIAS for module auto loading

On my ACPI based arm64 server, if the SMMUv3 PMU is configured as
module it won't be loaded automatically after booting even if the
device has already been scanned and added. It's because the module
lacks a platform alias, the uevent mechanism and userspace tools
like udevd make use of this to find the target driver module of the
device. This patch adds the missing platform alias of the module,
then module will be loaded automatically if device exists.

Before this patch:
[root@localhost tmp]# modinfo arm_smmuv3_pmu | grep alias
alias:          of:N*T*Carm,smmu-v3-pmcgC*
alias:          of:N*T*Carm,smmu-v3-pmcg

After this patch:
[root@localhost tmp]# modinfo arm_smmuv3_pmu | grep alias
alias:          platform:arm-smmu-v3-pmcg
alias:          of:N*T*Carm,smmu-v3-pmcgC*
alias:          of:N*T*Carm,smmu-v3-pmcg
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20230814131642.65263-1-yangyicong@huawei.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/arm_smmuv3_pmu.c

@@ -1028,6 +1028,7 @@ static void __exit arm_smmu_pmu_exit(void)
 
 module_exit(arm_smmu_pmu_exit);
 
+MODULE_ALIAS("platform:arm-smmu-v3-pmcg");
 MODULE_DESCRIPTION("PMU driver for ARM SMMUv3 Performance Monitors Extension");
 MODULE_AUTHOR("Neil Leeder <nleeder@codeaurora.org>");
 MODULE_AUTHOR("Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>");