nvmem: core: update raw_len if the bit reading is required

nvmem: core: update raw_len if the bit reading is required

If NVMEM cell uses bit offset or specifies bit truncation, update
raw_len manually (following the cell->bytes update), ensuring that the
NVMEM access is still word-aligned.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20250411112251.68002-11-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>