nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI

nvmem: apple-spmi-nvmem: wrap regmap calls to satisfy CFI

The Apple SPMI NVMEM driver previously cast regmap_bulk_read/write to
void * when assigning them to nvmem_config's reg_read/reg_write
function pointers.

This cast breaks the expected function signature of nvmem_reg_read_t
and nvmem_reg_write_t. With CFI enabled, indirect calls through
these pointers fail:

  CFI failure at nvmem_reg_write+0x194/0x1e4 (target: regmap_bulk_write+0x0/0x2c8; expected type: 0x83a189c3)
  ...
  Call trace:
   nvmem_reg_write+0x194/0x1e4 (P)
   __nvmem_cell_entry_write+0x298/0x2e8
   nvmem_cell_write+0x24/0x34
   macsmc_reboot_probe+0x1dc/0x454 [macsmc_reboot]
  ...

Introduce thin wrapper functions with the correct nvmem function
pointer types to satisfy the CFI checks.

Fixes: fe91c24a551c ("nvmem: Add apple-spmi-nvmem driver")
Signed-off-by: Aelin Reidel <aelin@mainlining.org>
Reported-by: Clayton Craft <craftyguy@postmarketos.org>
Tested-by: Clayton Craft <craftyguy@postmarketos.org>
Reviewed-by: Sven Peter <sven@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Srinivas Kandagatla <srini@kernel.org>
Link: https://patch.msgid.link/20260724223404.629248-2-srini@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>