misc: at24: Fix typo in at24 header file

This commit fixes a simple typo s/mvmem/nvmem in the
example.

Signed-off-by: Moritz Fischer <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

include/linux/platform_data/at24.h

···
  *
  * An example in pseudo code for a setup() callback:
  *
- * void get_mac_addr(struct mvmem_device *nvmem, void *context)
+ * void get_mac_addr(struct nvmem_device *nvmem, void *context)
  * {
  *	u8 *mac_addr = ethernet_pdata->mac_addr;
  *	off_t offset = context;