nvmem: add missing MODULE_DESCRIPTION() macros

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvmem/nvmem-apple-efuses.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvmem/nvmem_brcm_nvram.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/nvmem/nvmem_u-boot-env.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <[e-mail]>
Signed-off-by: Srinivas Kandagatla <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/nvmem/apple-efuses.c

···
 module_platform_driver(apple_efuses_driver);
 
 MODULE_AUTHOR("Sven Peter <[e-mail]>");
+MODULE_DESCRIPTION("Apple SoC eFuse driver");
 MODULE_LICENSE("GPL");

drivers/nvmem/brcm_nvram.c

···
 subsys_initcall_sync(brcm_nvram_init);
 
 MODULE_AUTHOR("Rafał Miłecki");
+MODULE_DESCRIPTION("Broadcom I/O-mapped NVRAM support driver");
 MODULE_LICENSE("GPL");
 MODULE_DEVICE_TABLE(of, brcm_nvram_of_match_table);

drivers/nvmem/u-boot-env.c

···
 module_platform_driver(u_boot_env_driver);
 
 MODULE_AUTHOR("Rafał Miłecki");
+MODULE_DESCRIPTION("U-Boot environment variables support module");
 MODULE_LICENSE("GPL");
 MODULE_DEVICE_TABLE(of, u_boot_env_of_match_table);