mmc: renesas_sdhi: Fix alignment check of sg buffer

Sometimes sg->offset is not used for buffer addresses allocated by
dma_map_sg(), so alignment checks should be done on the allocated buffer
addresses. Delete the alignment check for sg->offset that is done before
dma_map_sg(). Instead, it performs the alignment check for
sg->dma_address after dma_map_sg().

Signed-off-by: Masaharu Hayakawa <masaharu.hayakawa.ry@renesas.com>
[Niklas: broke this commit in two and tidied small style issue]
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
[rebased to mmc/next]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>