gpio/omap: fix build error with certain OMAP1 configs

With commit f64ad1a0, "gpio/omap: cleanup _set_gpio_wakeup(), remove
ifdefs", access to build time conditionally omitted 'suspend_wakeup'
member of the 'gpio_bank' structure has been placed unconditionally in
function _set_gpio_wakeup(), which is always built. This resulted in the
driver compilation broken for certain OMAP1, i.e., non-OMAP16xx,
configurations.

Really required or not in previously excluded cases, define this
structure member unconditionally as a fix.

Tested with a custom OMAP1510 only configuration.
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/gpio/gpio-omap.c

@@ -34,8 +34,8 @@ struct gpio_bank {
 	u16 irq;
 	u16 virtual_irq_start;
 	int method;
-#if defined(CONFIG_ARCH_OMAP16XX) || defined(CONFIG_ARCH_OMAP2PLUS)
 	u32 suspend_wakeup;
+#if defined(CONFIG_ARCH_OMAP16XX) || defined(CONFIG_ARCH_OMAP2PLUS)
 	u32 saved_wakeup;
 #endif
 	u32 non_wakeup_gpios;