MIPS: Kconfig: Add missing MODULES dependency to VPE_LOADER

The vpe.c code uses the 'struct module' which is only available if
CONFIG_MODULES is selected.

Also fixes the following build problem on a lantiq allmodconfig:
In file included from arch/mips/kernel/vpe.c:41:0:
include/linux/moduleloader.h: In function 'apply_relocate':
include/linux/moduleloader.h:48:63: error: dereferencing pointer
to incomplete type
include/linux/moduleloader.h: In function 'apply_relocate_add':
include/linux/moduleloader.h:70:63: error: dereferencing pointer
to incomplete type

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5562/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -1929,7 +1929,7 @@ config MIPS_MT_FPAFF
 
 config MIPS_VPE_LOADER
 	bool "VPE loader support."
-	depends on SYS_SUPPORTS_MULTITHREADING
+	depends on SYS_SUPPORTS_MULTITHREADING && MODULES
 	select CPU_MIPSR2_IRQ_VI
 	select CPU_MIPSR2_IRQ_EI
 	select MIPS_MT