mtd: parsers: qcom: Fix leaking of partition name

Add cleanup function as the name variable for the partition name was
allocaed but never freed after the use as the add mtd function
duplicate the name and free the pparts struct as the partition name is
assumed to be static.
The leak was found using kmemleak.

Fixes: 803eb124

 ("mtd: parsers: Add Qcom SMEM parser")
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210525230931.30013-1-ansuelsmth@gmail.com