mb/google/nissa/var/anraggar: Enable BT audio offload

This patch enables Cnvi BT Audio Offload feature and also
configures the virtual GPIO for CNVi Bluetooth I2S pads.

BUG=b:303157827
TEST=Build and boot to anraggar. Verify the config from serial logs.

w/o this CL -
```
[SPEW ]  -- CNVi Config --
[SPEW ]  CNVi Mode= 1
[SPEW ]  Wi-Fi Core= 1
[SPEW ]  BT Core= 1
[SPEW ]  BT Audio Offload= 0
[SPEW ]  Pin Muxing
```

w/ this CL -
```
[SPEW ]  -- CNVi Config --
[SPEW ]  CNVi Mode= 1
[SPEW ]  Wi-Fi Core= 1
[SPEW ]  BT Core= 1
[SPEW ]  BT Audio Offload= 1
[SPEW ]  Pin Muxing
```

Change-Id: I9e6731c8ceaad6ee58b525d4246fa769bfe1b0c7
Signed-off-by: Jianeng Ceng <cengjianeng@huaqin.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80001
Reviewed-by: Weimin Wu <wuweimin@huaqin.corp-partner.google.com>
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/brya/variants/anraggar/gpio.c

@@ -69,6 +69,24 @@ static const struct pad_config override_gpio_table[] = {
 	PAD_NC_LOCK(GPP_R6, NONE, LOCK_CONFIG),
 	/* R7 : DMIC_DATA_1A ==> NC */
 	PAD_NC_LOCK(GPP_R7, NONE, LOCK_CONFIG),
+
+	/* Configure the virtual CNVi Bluetooth I2S GPIO pads */
+	/* BT_I2S_BCLK */
+	PAD_CFG_NF(GPP_VGPIO_30, NONE, DEEP, NF3),
+	/* BT_I2S_SYNC */
+	PAD_CFG_NF(GPP_VGPIO_31, NONE, DEEP, NF3),
+	/* BT_I2S_SDO */
+	PAD_CFG_NF(GPP_VGPIO_32, NONE, DEEP, NF3),
+	/* BT_I2S_SDI */
+	PAD_CFG_NF(GPP_VGPIO_33, NONE, DEEP, NF3),
+	/* SSP2_SCLK */
+	PAD_CFG_NF(GPP_VGPIO_34, NONE, DEEP, NF1),
+	/* SSP2_SFRM */
+	PAD_CFG_NF(GPP_VGPIO_35, NONE, DEEP, NF1),
+	/* SSP_TXD */
+	PAD_CFG_NF(GPP_VGPIO_36, NONE, DEEP, NF1),
+	/* SSP_RXD */
+	PAD_CFG_NF(GPP_VGPIO_37, NONE, DEEP, NF1),
 };
 
 /* Early pad configuration in bootblock */

src/mainboard/google/brya/variants/anraggar/overridetree.cb

@@ -81,6 +81,9 @@ chip soc/intel/alderlake
 		.configure_ext_fivr = 0,
 	}"
 
+	# Enable the Cnvi BT Audio Offload
+	register "cnvi_bt_audio_offload" = "1"
+
 	# Intel Common SoC Config
 	#+-------------+------------------------------+
 	#| Field	|  Value			|