ARM: tegra: common: Set SCLK to 40MHz for spi

Setting sclk frequency for spi to 40MHz.

bug 949393

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/89525
cherry-picked from
	171f5693e4137e9fe5a8b4e496c0c5db3b7838f1

Change-Id: I34808a64b834111dfff1592dd9244a45e9d3312c
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/90295
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>

Rebase-Id: Raa51a7136ff54a83b34a41b3c530deab47515652