arch/arm/cpu/armv7/omap-common/spl.c: Fix GCC 4.2 warnings

Fix:
spl.c: In function 'jump_to_image_no_args':
spl.c:103: warning: assignment makes pointer from integer without a cast
spl.c:105: warning: dereferencing type-punned pointer will break
strict-aliasing rules

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>