mfd: sec: Merge separate core and irq modules

mfd: sec: Merge separate core and irq modules

There is no reason to have these two kernel modules separate. Having
them merged into one kernel module also slightly reduces memory
consumption and module load times a little.

mapped size (lsmod):
         before:             after:
    sec_core   20480    sec_core   24576
    sec_irq    16384
    ----------------
    total      36864

Section sizes (size -A):
         before:             after:
    sec_core    6780    sec_core   13239
    sec_irq     8046
    ----------------
    Total      14826

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250409-s2mpg10-v4-10-d66d5f39b6bf@linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>