perf: MARVELL_CN10K_TAD_PMU should depend on ARCH_THUNDER

The Marvell CN10K Last-Level cache Tag-and-data Units (LLC-TAD)
performance monitor is only present on Marvell CN10K SoCs.  Hence add a
dependency on ARCH_THUNDER, to prevent asking the user about this driver
when configuring a kernel without Cavium Thunder (incl. Marvell CN10K)
SoC support.

Fixes: 036a7584 ("drivers: perf: Add LLC-TAD perf counter support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/b4662a2c767d04cca19417e0c845edea2da262ad.1641995941.git.geert+renesas@glider.beSigned-off-by: Will Deacon <will@kernel.org>

drivers/perf/Kconfig

@@ -141,7 +141,7 @@ config ARM_DMC620_PMU
 
 config MARVELL_CN10K_TAD_PMU
 	tristate "Marvell CN10K LLC-TAD PMU"
-	depends on ARM64 || (COMPILE_TEST && 64BIT)
+	depends on ARCH_THUNDER || (COMPILE_TEST && 64BIT)
 	help
 	  Provides support for Last-Level cache Tag-and-data Units (LLC-TAD)
 	  performance monitors on CN10K family silicons.