perf: xgene: Include module.h

I ran into a build error when I disabled CONFIG_ACPI and tried to
compile this driver:

drivers/perf/xgene_pmu.c:1242:1: warning: data definition has no type or storage class
 MODULE_DEVICE_TABLE(of, xgene_pmu_of_match);
 ^
drivers/perf/xgene_pmu.c:1242:1: error: type defaults to 'int' in declaration of 'MODULE_DEVICE_TABLE' [-Werror=implicit-int]

Include module.h for the MODULE_DEVICE_TABLE macro that's
implicitly included through ACPI.

Tested-by: Tai Nguyen <ttnguyen@apm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>