plat: imx8mm: update the stby_count setting

The reset value of the STBY_COUNT is 0x0, so
it means GPC will wait for 4 ckil(32K) clock cycle
before checking the PMIC ready signal. increase
this value to 0x5, 128 ckil to make sure PMIC
output voltage is stable before GPC continue
to finish the DSM exit flow.

Signed-off-by: Jacky Bai <>
(cherry picked from commit 94f65be918f91df676f0e61c4fef97dfd31e168f)
1 file changed