sh: Only build in gpio.o when CONFIG_GENERIC_GPIO is selected.

The pinmux management is tied in to this code, while it is presently only
used by platforms that select GENERIC_GPIO. The asm/gpio.h definitions
are not referenced when GENERIC_GPIO is disabled, resulting in a build
failure for all of the platforms that don't select it.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/Makefile_32

@@ -5,7 +5,7 @@
 extra-y	:= head_32.o init_task.o vmlinux.lds
 
 obj-y	:= debugtraps.o io.o io_generic.o irq.o machvec.o process_32.o \
-	   ptrace_32.o setup.o signal_32.o sys_sh.o sys_sh32.o gpio.o \
+	   ptrace_32.o setup.o signal_32.o sys_sh.o sys_sh32.o \
 	   syscalls_32.o time_32.o topology.o traps.o traps_32.o
 
 obj-y				+= cpu/ timers/
@@ -23,5 +23,6 @@ obj-$(CONFIG_PM)		+= pm.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_IO_TRAPPED)	+= io_trapped.o
 obj-$(CONFIG_KPROBES)		+= kprobes.o
+obj-$(CONFIG_GENERIC_GPIO)	+= gpio.o
 
 EXTRA_CFLAGS += -Werror

arch/sh/kernel/Makefile_64

 extra-y	:= head_64.o init_task.o vmlinux.lds
 
 obj-y	:= debugtraps.o io.o io_generic.o irq.o machvec.o process_64.o \
-	   ptrace_64.o setup.o signal_64.o sys_sh.o sys_sh64.o gpio.o \
+	   ptrace_64.o setup.o signal_64.o sys_sh.o sys_sh64.o \
 	   syscalls_64.o time_64.o topology.o traps.o traps_64.o
 
 obj-y				+= cpu/ timers/
@@ -18,5 +18,6 @@ obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_PM)		+= pm.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-$(CONFIG_IO_TRAPPED)	+= io_trapped.o
+obj-$(CONFIG_GENERIC_GPIO)	+= gpio.o
 
 EXTRA_CFLAGS += -Werror