sbus: add missing MODULE_DESCRIPTION() macros

With ARCH=sparc, make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/sbus/char/envctrl.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/sbus/char/flash.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/sbus/char/uctrl.o
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/sbus/char/bbc.o

Add the missing invocations of the MODULE_DESCRIPTION() macro.
Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Reviewed-by: Andreas Larsson <andreas@gaisler.com>
Link: https://lore.kernel.org/r/20240619-md-sparc-drivers-sbus-char-v1-1-85acadb8f789@quicinc.comSigned-off-by: Andreas Larsson <andreas@gaisler.com>

drivers/sbus/char/bbc_i2c.c

@@ -418,4 +418,5 @@ static struct platform_driver bbc_i2c_driver = {
 
 module_platform_driver(bbc_i2c_driver);
 
+MODULE_DESCRIPTION("UltraSPARC-III bootbus i2c controller driver");
 MODULE_LICENSE("GPL");

drivers/sbus/char/envctrl.c

@@ -1130,4 +1130,5 @@ static struct platform_driver envctrl_driver = {
 
 module_platform_driver(envctrl_driver);
 
+MODULE_DESCRIPTION("SUN environment monitoring device driver");
 MODULE_LICENSE("GPL");

drivers/sbus/char/flash.c

@@ -211,4 +211,5 @@ static struct platform_driver flash_driver = {
 
 module_platform_driver(flash_driver);
 
+MODULE_DESCRIPTION("OBP Flash Device driver");
 MODULE_LICENSE("GPL");

drivers/sbus/char/uctrl.c

@@ -431,4 +431,5 @@ static struct platform_driver uctrl_driver = {
 
 module_platform_driver(uctrl_driver);
 
+MODULE_DESCRIPTION("Tadpole TS102 Microcontroller driver");
 MODULE_LICENSE("GPL");