mks_canable_v20: fix fdcan1 clock select

Use STM32_CLOCK() clock select macro with bit-25
set.
This change shall set register RCC_CCIPR->FDCANSEL
to 0x01.
Previosuly there were bit-12 set, which was wrong.
For more information refer to RM0440 Rev. 8
page 323 of 2138.

Signed-off-by: Alexander Kozhinov <ak.alexander.kozhinov@gmail.com>