soc: qcom: pil: Avoid memory leaks by releasing the firmware resources

Currently, the driver calls request_firmware_into_buf() to load
the firmware image onto a pre-allocated memory. During the
process, some firmware resources are created. Usually, it
should be freed by a call to release_firmware() once the
firmware is loaded. However, the driver doesn't do this.
Hence, the memory is leaked each time a subsystem powerup
handling path is triggered (from a restart or a crash handling).
Therefore, release the firmware resources once the firmware is
loaded onto the memory.

Change-Id: I565afeda1157c9f7952336462ae0b022a2eca0bd
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>