[pauthabi64] Remove relocation RAARCH64_AUTH_GOT_ADD_LO12_NC

There is no equivalent for this relocation in the standard ABI
it could be used for runtime code to calculate the address of
a GOT slot in a similar way to obtaining the address of a
static data item. However there is no way to express the
address of a GOT slot in source code, and the compiler can
use a load to get the contents of the GOT slot directly
without first calculating the address.

Part of #253

pauthabielf64/pauthabielf64.rst

@@ -1163,10 +1163,6 @@ The GOT entries must be relocated by AUTH variant dynamic relocations.
   |             |                                        |                                  | X; check that 0 <= X  <  |
   |             |                                        |                                  | 2\ :sup:`15`             |
   +-------------+----------------------------------------+----------------------------------+--------------------------+
-  | 0x811C      | R\AARCH64\_AUTH\_GOT\_ADD_LO12_NC      | G(ENCD(GDAT(S + A)))             | Set an ADD immediate     |
-  |             |                                        |                                  | value to bits [11:0] of  |
-  |             |                                        |                                  | X. No overflow check.    |
-  +-------------+----------------------------------------+----------------------------------+--------------------------+
 
 .. raw:: pdf