ufs: fix power info after link start-up

After link start-up power mode will always be PWM G1. This is not
reflected in the pwr_info struct which will keep the previous values.
Since ufshcd_change_power_mode() tries to avoid unnecessary power mode
change if the requested power mode and current power mode are same,
power mode change won't execute again after driver initialization.

This patch solves the problem by setting pwr_info to PWM G1 after link
start-up.

Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Reviewed-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>