treewide: Remove "ERROR: "/"WARN: " prefixes from log messages

Now that the console system itself will clearly differentiate loglevels,
it is no longer necessary to explicitly add "ERROR: " in front of every
BIOS_ERR message to help it stand out more (and allow automated tooling
to grep for it). Removing all these extra .rodata characters should save
us a nice little amount of binary size.

This patch was created by running

  find src/ -type f -exec perl -0777 -pi -e 's/printk\(\s*BIOS_ERR,\s*"ERROR: /printk\(BIOS_ERR, "/gi' '{}' ';'

and doing some cursory review/cleanup on the result. Then doing the same
thing for BIOS_WARN with

  's/printk\(\s*BIOS_WARNING,\s*"WARN(ING)?: /printk\(BIOS_WARNING, "/gi'

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I3d0573acb23d2df53db6813cb1a5fc31b5357db8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61309
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Lance Zhao
Reviewed-by: Jason Glenesk <jason.glenesk@gmail.com>

src/acpi/acpigen.c

@@ -1783,7 +1783,7 @@ void acpigen_write_CPPC_package(const struct cppc_config *config)
 		max = CPPC_MAX_FIELDS_VER_3;
 		break;
 	default:
-		printk(BIOS_ERR, "ERROR: CPPC version %u is not implemented\n",
+		printk(BIOS_ERR, "CPPC version %u is not implemented\n",
 		       config->version);
 		return;
 	}