ARM: fix Kconfig warning for HAVE_BPF_JIT

Last night's randconfig and the allnoconfig builds spat out the
following warning while building:

warning: (ARM) selects HAVE_BPF_JIT which has unmet direct dependencies (NET)
Acked-by: Mircea Gherzan <mgherzan@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/Kconfig

@@ -34,7 +34,7 @@ config ARM
 	select GENERIC_IRQ_SHOW
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select GENERIC_PCI_IOMAP
-	select HAVE_BPF_JIT
+	select HAVE_BPF_JIT if NET
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and