cores/usb: Minor documentation syntax fixes in markdown

Setting type to text since the auto-detect can get confused ...

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>

cores/usb/doc/mem-map.md

@@ -6,7 +6,7 @@ Global CSRs
 
 ### Control / Status (Read / Write addr `0x00`)
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|
@@ -28,7 +28,7 @@ Global CSRs
 
 ### Action ( Write addr `0x01` )
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|
@@ -52,7 +52,7 @@ the core configuration.
 
 Count mode (`EVENT_DEPTH = 0/1`) :
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|
@@ -66,7 +66,7 @@ Count mode (`EVENT_DEPTH = 0/1`) :
 
 FIFO mode (`EVENT_DEPTH > 1`) :
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|
@@ -81,7 +81,7 @@ FIFO mode (`EVENT_DEPTH > 1`) :
 
 Event format:
 
-```
+```text
 ,-----------------------------------------------,
 | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |-----------------------------------------------|
@@ -101,7 +101,7 @@ EP Status
 
 ### Address:
 
-```
+```text
 ,-----------------------------------------------,
 | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |-----------------------------------------------|
@@ -112,7 +112,7 @@ EP Status
 
 ### Data:
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|
@@ -139,7 +139,7 @@ Buffer Descriptor
 
 ### Address:
 
-```
+```text
 ,-----------------------------------------------,
 | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |-----------------------------------------------|
@@ -153,7 +153,7 @@ Buffer Descriptor
 
 ### Word 0:
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|
@@ -172,7 +172,7 @@ Buffer Descriptor
 
 ### Word 1:
 
-```
+```text
 ,---------------------------------------------------------------,
 | f | e | d | c | b | a | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
 |---------------------------------------------------------------|