spi: Tegra2: increase SPI FLASH clock to 24MHz

Signed-off-by: Tom Warren <twarren@nvidia.com>

R=robotboy@chromium.org
BUG=none
TEST=Added timestamps around SPI env read (128K) and saw the time cut in half

Review URL: http://codereview.chromium.org/6670098
Patch from Tom Warren <twarren@nvidia.com>.

Change-Id: I345d56c9cc3b92005889c865e42a89aacc28546e
1 file changed