LED drivers: update PWM register defines for g_<driver>_leds

[fauxpark]

Description

These drivers have a mixture of naming conventions for the PWM register defines used for mapping LED channels. Some use an alphanumeric "matrix location" (A_1 etc), where others use CSx_SWy. The latter is almost correct but should be flipped (SWx_CSy) to better reflect the ordering.

This is an effort to clarify and "standardise" them, by using the pin names from the datasheet instead which should be less prone to naming collisions.

AW20216S: CS1_SW1-CS18_SW12 -> SW1_CS1-SW12_CS18
IS31FL3733: A_1-L_16 -> SW1_CS1-SW12_CS16
IS31FL3736: A_1-L_8 -> SW1_CS1-SW12_CS8
IS31FL3737: A_1-L_12 -> SW1_CS1-SW12_CS12
IS31FL3742A: CS1_SW1-CS30_SW6 -> SW1_CS1-SW6_CS30
IS31FL3743A: CS1_SW1-CS18_SW11 -> SW1_CS1-SW11_CS18
IS31FL3745: CS1_SW1-CS18_SW8 -> SW1_CS1-SW8_CS18
IS31FL3746A: CS1_SW1-CS18_SW4 -> SW1_CS1-SW4_CS18
SNLED27351: A_1-L_16 -> CB1_CA1-CB12_CA16

IS31FL3731 uses a charlieplex configuration; for now I have left it alone but may revisit it.
IS31FL3741 is waiting on #23049 which also touches these defines.

Defines for backwards compatibility have been added for the drivers currently used in the repo.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).