arch/arm/cpu/armv7/omap-common/clocks-common.c: Fix GCC 4.6 warnings

Fix:
clocks-common.c: In function 'setup_dplls':
clocks-common.c:256:6: warning: variable 'sysclk_ind' set but not used
[-Wunused-but-set-variable]
clocks-common.c: In function 'setup_non_essential_dplls':
clocks-common.c:292:6: warning: variable 'sysclk_ind' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: sricharan <r.sricharan@ti.com>
Cc: Tom Rini <trini@ti.com>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Acked-by: Tom Rini <trini@ti.com>