Missing bit-field descriptions for SPI uDMA commands in documentation

[mdjannatulnayem]

The current documentation for the SPI uDMA command list (section 4.8.17) provides detailed bit-field information for some commands like SPI_CMD_CFG, SPI_CMD_SOT, SPI_CMD_SEND_CMD, and SPI_CMD_DUMMY.

However, the bit-field layouts for the remaining commands such as SPI_CMD_WAIT, SPI_CMD_TX_DATA, SPI_CMD_RX_DATA, SPI_CMD_RPT, SPI_CMD_EOT, SPI_CMD_RPT_END, SPI_CMD_RX_CHECK, SPI_CMD_FULL_DUPL, SPI_CMD_SETUP_UCA, and SPI_CMD_SETUP_UCS are missing.

Without this information, it is difficult to correctly format uDMA command streams for these operations, which limits proper usage of the SPI module in automated or complex transactions.

Expected behavior:
Each uDMA SPI command in the documentation should include:

• Bit-field layout (bit positions and sizes)
• Detailed description for each field (e.g., meaning of flags, valid ranges, special behavior)

Affected commands:

• SPI_CMD_WAIT
• SPI_CMD_TX_DATA
• SPI_CMD_RX_DATA
• SPI_CMD_RPT
• SPI_CMD_EOT
• SPI_CMD_RPT_END
• SPI_CMD_RX_CHECK
• SPI_CMD_FULL_DUPL
• SPI_CMD_SETUP_UCA
• SPI_CMD_SETUP_UCS

Reference:
Section 4.8.17–4.8.21 of the current documentation contains partial details for commands but does not include the bit-field mappings for the commands listed above.

Proposed solution:
Update the documentation with complete bit-field diagrams and field descriptions for all SPI uDMA commands.