remoteproc: correct rproc_mem_entry_init() comments

Add alloc parameter description and correct comment
about release one.
Signed-off-by: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/remoteproc/remoteproc_core.c

@@ -944,7 +944,8 @@ EXPORT_SYMBOL(rproc_add_carveout);
  * @dma: dma address
  * @len: memory carveout length
  * @da: device address
- * @release: memory carveout function
+ * @alloc: memory carveout allocation function
+ * @release: memory carveout release function
  * @name: carveout name
  *
  * This function allocates a rproc_mem_entry struct and fill it with parameters