wifi: mt76: Strip whitespace from build ddate

On systems I have with mt7925 cards I've been noticing a blank line in my
kernel logs.  IE:
```
[   17.294105] mt7925e 0000:c3:00.0: HW/SW Version: 0x8a108a10, Build Time: 20250721232852a

[   17.314233] r8169 0000:c4:00.0 enp196s0f0: Link is Down
```

This is because the build_date from the header has a newline character
as does the dev_info() print.  As the firmware isn't guaranteed to always
have a newline but the print is, copy the firmware build date to a
temporary variable and strip any whitespace from it before showing it in
the logs.

Signed-off-by: Mario Limonciello (AMD) <superm1@kernel.org>
Link: https://patch.msgid.link/20251120155829.3494747-1-superm1@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>

Author: superm1

drivers/net/wireless/mediatek/mt76/mt76_connac_mcu.c

@@ -3101,6 +3101,7 @@ int mt76_connac2_load_patch(struct mt76_dev *dev, const char *fw_name)
 	int i, ret, sem, max_len = mt76_is_sdio(dev) ? 2048 : 4096;
 	const struct mt76_connac2_patch_hdr *hdr;
 	const struct firmware *fw = NULL;
+	char build_date[17];
 
 	sem = mt76_connac_mcu_patch_sem_ctrl(dev, true);
 	switch (sem) {
@@ -3124,8 +3125,11 @@ int mt76_connac2_load_patch(struct mt76_dev *dev, const char *fw_name)
 	}
 
 	hdr = (const void *)fw->data;
+	strscpy(build_date, hdr->build_date, sizeof(build_date));
+	build_date[16] = '\0';
+	strim(build_date);
 	dev_info(dev->dev, "HW/SW Version: 0x%x, Build Time: %.16s\n",
-		 be32_to_cpu(hdr->hw_sw_ver), hdr->build_date);
+		 be32_to_cpu(hdr->hw_sw_ver), build_date);
 
 	for (i = 0; i < be32_to_cpu(hdr->desc.n_region); i++) {
 		struct mt76_connac2_patch_sec *sec;