crypto: arm/curve25519 - rename 'mod_init' & 'mod_exit' functions to be module-specific

Rename module_init & module_exit functions that are named
"mod_init" and "mod_exit" so that they are unique in both the
System.map file and in initcall_debug output instead of showing
up as almost anonymous "mod_init".

This is helpful for debugging and in determining how long certain
module_init calls take to execute.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: patches@armlinux.org.uk
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>