mdss: dsi: Handle gpio configuration properly

Dsi related GPIOs are freed even when gpio request fails.
Fix this by removing the gpio_free() calls when the gpio request
fails. Add the gpio_request() and gpio_free()
calls to panel reset sequence so that gpio pins would
go to suspend state when not in use.

Change-Id: Id5ef45c5cc106d2a3ced3359739037f488e1919f
Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>