platform/mellanox: mlxreg-hotplug: Enable building for ARM

Add ARM in addition to X86 as supported architectures in the Mellanox
Hotplug Platform driver Kconfig entry.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
[dvhart: rewrite commit message]
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

drivers/platform/mellanox/Kconfig

@@ -5,7 +5,7 @@
 
 menuconfig MELLANOX_PLATFORM
 	bool "Platform support for Mellanox hardware"
-	depends on X86 || COMPILE_TEST
+	depends on X86 || ARM || COMPILE_TEST
 	---help---
 	  Say Y here to get to see options for platform support for
 	  Mellanox systems. This option alone does not add any kernel code.