lib/crypto: arm/poly1305: Remove unneeded empty weak function

lib/crypto: arm/poly1305: Remove unneeded empty weak function

Fix poly1305-armv4.pl to not do '.globl poly1305_blocks_neon' when
poly1305_blocks_neon() is not defined.  Then, remove the empty __weak
definition of poly1305_blocks_neon(), which was still needed only
because of that unnecessary globl statement.  (It also used to be needed
because the compiler could generate calls to it when
CONFIG_KERNEL_MODE_NEON=n, but that has been fixed.)

Thanks to Arnd Bergmann for reporting that the globl statement in the
asm file was still depending on the weak symbol.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250711212822.6372-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>