thermal/drivers/k3_j72xx_bandgap: Make k3_j72xx_bandgap_j721e_data and k3_j72xx_bandgap_j7200_data static

Fix sparse warnings:

drivers/thermal/k3_j72xx_bandgap.c:532:36: sparse: sparse: symbol 'k3_j72xx_bandgap_j721e_data' was not declared. Should it be static?
drivers/thermal/k3_j72xx_bandgap.c:536:36: sparse: sparse: symbol 'k3_j72xx_bandgap_j7200_data' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jin Xiaoyun <jinxiaoyun2@huawei.com>
Link: https://lore.kernel.org/r/20220613063111.654893-1-jinxiaoyun2@huawei.comSigned-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>