An upcoming silicon change places a number of existing blocks within the
Venus at different relative offsets to the base address of IO region.

In order to handle this difference this patch changes the address offsets
of the registers to function as offsets relative to the relevant sub-block
of registers within the IO region not the base address of the IO region.

As a result of this change venus_readl() and venus_writel() are deleted.
Co-developed-by: Dikshita Agarwal <dikshita@codeaurora.org>
Signed-off-by: Dikshita Agarwal <dikshita@codeaurora.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>