Add gis module, current gis is support vadc input.
Add power down function to lcdif driver.

Signed-off-by: Sandor Yu <R01008@freescale.com>
Signed-off-by: Ye.Li <B37916@freescale.com>
(cherry picked from commit a007b00dd8ef9f773dfdebef0b1deb0990281793)
(cherry picked from commit a31dcdafb0963381e7213c59f79a340ef27ec2e2)
(cherry picked from commit 02dfe2e4af5f51d39a51542fb0e81f93faf505bc)