Fix OLED support for mechwild/murphpad.

[marcelmaltry]

OLED on mechwild/murphpad:vial was not activated due to use of OLED_DRIVER_ENABLE instead of OLED_ENABLE in keymap.c.

[xyzz]

Looks like the build is failing here

2021-12-24T19:55:33.3954184Z Checking file size of mechwild_murphpad_vial.hex                                                   
2021-12-24T19:55:33.3955204Z  * �[31;01mThe firmware is too large!�[0m 28862/28672 (190 bytes over)
2021-12-24T19:55:33.3967026Z  �[31;01m[ERRORS]�[0m

[marcelmaltry]

Is there a particular reason why your CI uses avr-gcc (GCC) 5.4.0? The firmware compiles fine here locally with avr-gcc (Homebrew AVR GCC 8.4.0_2) 8.4.0.

 * The firmware size is approaching the maximum - 28324/28672 (98%, 348 bytes free)

[xyzz]

It's using the qmkfm/base_container docker so that our CI matches qmk's -

vial-qmk/.github/workflows/ci.yml

Line 12 in 1998b3e

container: qmkfm/base_container

there are plans to replace it with a unified toolchain (so we can ship same version of GCC for windows/mac/linux), though that's far away