[media] mtk-vcodec: fix more type mismatches

The newly added mtk-vcodec driver produces a number of warnings in an
ARM allmodconfig build, mainly since it assumes that dma_addr_t is
32-bit wide:

mtk-vcodec/venc/venc_vp8_if.c: In function 'vp8_enc_alloc_work_buf':
mtk-vcodec/venc/venc_vp8_if.c:212:191: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]
mtk-vcodec/venc/venc_h264_if.c: In function 'h264_enc_alloc_work_buf':
mtk-vcodec/venc/venc_h264_if.c:297:190: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast]

This rearranges the format strings and type casts to what they should
have been in order to avoid the warnings. e0f80d8d ("[media]
mtk-vcodec: fix two compiler warnings") fixed some of the problems that
were introduced at the same time, but missed two others.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>