media: platform: fix some 64-bits warnings

media: platform: fix some 64-bits warnings

The omap/omap3 and viu drivers are for 32 bit platforms only.
There, a pointer has 32 bits. Now that those drivers build
for 64 bits with COMPILE_TEST, they produce the following
warnings:

drivers/media/platform/omap/omap_vout_vrfb.c: In function 'omap_vout_allocate_vrfb_buffers':
drivers/media/platform/omap/omap_vout_vrfb.c:57:10: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   memset((void *) vout->smsshado_virt_addr[i], 0,
          ^
drivers/media/platform/fsl-viu.c: In function 'viu_setup_preview':
drivers/media/platform/fsl-viu.c:753:28: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
  reg_val.field_base_addr = (u32)dev->ovbuf.base;
                            ^
drivers/media/platform/omap/omap_vout.c: In function 'omap_vout_get_userptr':
drivers/media/platform/omap/omap_vout.c:209:25: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
   *physp = virt_to_phys((void *)virtp);
                         ^
drivers/media/platform/omap3isp/ispccdc.c: In function 'ccdc_config':
drivers/media/platform/omap3isp/ispccdc.c:738:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
         (__force void __user *)fpc.fpcaddr,
         ^

Add some typecasts to remove those warnings when building for
64 bits.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>