Change all assert(0) to BUG()

I would like to make assertions evaluate at compile time where possible,
but sometimes people used a literal assert(0) to force an assertion in a
certain code path. We already have BUG() for that so let's just replace
those instances with that.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I674e5f8ec7f5fe8b92b1c7c95d9f9202d422ce32
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44047
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/soc/mediatek/mt8183/mt6358.c

@@ -831,7 +831,7 @@ void pmic_set_vsim2_cali(unsigned int vsim2_mv)
 		break;
 
 	default:
-		assert(0);
+		BUG();
 		return;
 	};