[MIPS] TXx9: Miscellaneous build fixes

* Fix build if only RBTX4927 or RBTX4938 was selected.
* Move gpio helpers to generic part.
* Select SOC_TX4938 for RBTX4927/37 board.
* Fix parent of rbtx4938_fpga_resource.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/txx9/generic/setup.c b/arch/mips/txx9/generic/setup.c
index 5afc5d5..8caef07 100644
--- a/arch/mips/txx9/generic/setup.c
+++ b/arch/mips/txx9/generic/setup.c
@@ -94,6 +94,22 @@
 }
 EXPORT_SYMBOL(clk_put);
 
+/* GPIO support */
+
+#ifdef CONFIG_GENERIC_GPIO
+int gpio_to_irq(unsigned gpio)
+{
+	return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_to_irq);
+
+int irq_to_gpio(unsigned irq)
+{
+	return -EINVAL;
+}
+EXPORT_SYMBOL(irq_to_gpio);
+#endif
+
 extern struct txx9_board_vec jmr3927_vec;
 extern struct txx9_board_vec rbtx4927_vec;
 extern struct txx9_board_vec rbtx4937_vec;
@@ -126,15 +142,19 @@
 #endif
 #ifdef CONFIG_CPU_TX49XX
 	switch (TX4938_REV_PCODE()) {
+#ifdef CONFIG_TOSHIBA_RBTX4927
 	case 0x4927:
 		txx9_board_vec = &rbtx4927_vec;
 		break;
 	case 0x4937:
 		txx9_board_vec = &rbtx4937_vec;
 		break;
+#endif
+#ifdef CONFIG_TOSHIBA_RBTX4938
 	case 0x4938:
 		txx9_board_vec = &rbtx4938_vec;
 		break;
+#endif
 	}
 #endif