struct clockdomain member clktrctrl_mask is available for only for OMAP2
and OMAP3 architectures. Technially it is also used only for these archs
but this breaks the build with custom OMAP4 configuration.

 CC      arch/arm/mach-omap2/clockdomain.o
arch/arm/mach-omap2/clockdomain.c: In function '_enable_hwsup':
arch/arm/mach-omap2/clockdomain.c:251: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c:254: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c: In function '_disable_hwsup':
arch/arm/mach-omap2/clockdomain.c:277: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c:280: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c: In function 'omap2_clkdm_sleep':
arch/arm/mach-omap2/clockdomain.c:744: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c: In function 'omap2_clkdm_wakeup':
arch/arm/mach-omap2/clockdomain.c:789: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c: In function 'omap2_clkdm_clk_enable':
arch/arm/mach-omap2/clockdomain.c:922: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c:926: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c: In function 'omap2_clkdm_clk_disable':
arch/arm/mach-omap2/clockdomain.c:994: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
arch/arm/mach-omap2/clockdomain.c:998: error: 'struct clockdomain' has no member named 'clktrctrl_mask'
make[1]: *** [arch/arm/mach-omap2/clockdomain.o] Error 1
make: *** [arch/arm/mach-omap2] Error 2

Fix the build break by dropping the #ifdef as suggested by Paul Walmsley

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>