esp_timer, hal: add support for non-integer systimer frequency

When ESP32-C2 is paired with a 26 MHz XTAL, the systimer tick
frequency becomes equal to 26 / 2.5 = 10.4 MHz. Previously we always
assumed that systimer tick frequency is integer (and 1 MHz * power of
two, above that!).
This commit introduces a new LL macro, SYSTIMER_LL_TICKS_PER_US_DIV.
It should be set in such a way that:

1. SYSTIMER_LL_TICKS_PER_US / SYSTIMER_LL_TICKS_PER_US_DIV equals the
   actual systimer tick frequency,
2. and SYSTIMER_LL_TICKS_PER_US is integer.

For ESP32-C2 this means that SYSTIMER_LL_TICKS_PER_US = 52 and
SYSTIMER_LL_TICKS_PER_US_DIV = 5.

This introduced two possible issues:

1. Overflow when multiplying systimer counter by 5
   - Should not be an issue, since systimer counter is 52-bit, so
     counter * 5 is no more than 55-bit.
2. The code needs to perform:
   - divide by 5: when converting from microseconds to ticks
   - divide by 52: when converting from ticks to microseconds
   The latter potentially introduces a performance issue for the
   esp_timer_get_time function.

components/soc/esp32s3/include/soc/Kconfig.soc_caps.in

@@ -679,9 +679,9 @@ config SOC_SYSTIMER_BIT_WIDTH_HI
     int
     default 20
 
-config SOC_SYSTIMER_FIXED_TICKS_US
-    int
-    default 16
+config SOC_SYSTIMER_HAS_FIXED_TICKS_PER_US
+    bool
+    default y
 
 config SOC_SYSTIMER_INT_LEVEL
     bool

components/soc/esp32s3/include/soc/soc_caps.h

@@ -277,14 +277,14 @@
 #define SOC_SPIRAM_SUPPORTED            1
 
 /*-------------------------- SYS TIMER CAPS ----------------------------------*/
-#define SOC_SYSTIMER_SUPPORTED             1
-#define SOC_SYSTIMER_COUNTER_NUM           (2)  // Number of counter units
-#define SOC_SYSTIMER_ALARM_NUM             (3)  // Number of alarm units
-#define SOC_SYSTIMER_BIT_WIDTH_LO          (32) // Bit width of systimer low part
-#define SOC_SYSTIMER_BIT_WIDTH_HI          (20) // Bit width of systimer high part
-#define SOC_SYSTIMER_FIXED_TICKS_US        (16) // Number of ticks per microsecond is fixed
-#define SOC_SYSTIMER_INT_LEVEL             (1)  // Systimer peripheral uses level
-#define SOC_SYSTIMER_ALARM_MISS_COMPENSATE (1)  // Systimer peripheral can generate interrupt immediately if t(target) > t(current)
+#define SOC_SYSTIMER_SUPPORTED              1
+#define SOC_SYSTIMER_COUNTER_NUM            (2)  // Number of counter units
+#define SOC_SYSTIMER_ALARM_NUM              (3)  // Number of alarm units
+#define SOC_SYSTIMER_BIT_WIDTH_LO           (32) // Bit width of systimer low part
+#define SOC_SYSTIMER_BIT_WIDTH_HI           (20) // Bit width of systimer high part
+#define SOC_SYSTIMER_HAS_FIXED_TICKS_PER_US (1)  // Number of ticks per microsecond is fixed (16 ticks/us)
+#define SOC_SYSTIMER_INT_LEVEL              (1)  // Systimer peripheral uses level
+#define SOC_SYSTIMER_ALARM_MISS_COMPENSATE  (1)  // Systimer peripheral can generate interrupt immediately if t(target) > t(current)
 
 /*-------------------------- TIMER GROUP CAPS --------------------------------*/
 #define SOC_TIMER_GROUPS                  (2)